England and Australia met on day two at Trent Bridge with the first Test of the Ashes series delicately poised following an absorbing first day in Nottingham.
The hosts started the day brilliantly, restricting Australia to 117-9 but a record-breaking knock of 98 from Ashton Agar helped the tourists to a score of 280.
England looked rattled by Agar's heroics and they fell further behind their rivals when Mitchell Starc took two early wickets in the second innings.
However, Alastair Cook (37*) and Kevin Pietersen (35*) steadied the ship in the final session of the day to guide their side to 80-2, a lead of 15, at the close of play.
Read below to find out how the drama unfolded on day two.
Hello, and welcome to Sports Mole's coverage of day two of the first Ashes Test match between England and Australia.
The opening day at Trent Bridge threw up plenty of excitement for both sets of supporters. Would it be asking too much if we requested the same today?
First things first, and this will come as no surprise to anyone, but the sun is out in Nottingham, which can only help the Australia batsmen. The cloudy conditions resulted in plenty of swing for the pace bowlers yesterday, but it could be a different story on day two.
Australia closed the opening day on 75-4, which leaves them 140 runs behind their hosts. If the sun remains out throughout the day, you would expect Australia to build a lead, because as was highlighted at the toss, this should be a pretty decent wicket for the opening few days.
Australia coach Darren Lehman insisted that the 'honours were even' after the opening three sessions, and on reflection, that is probably true, but it will only take a significant partnership or three wickets in 15 minutes to hand either side the advantage.
Despite the overhead conditions during Wednesday, it is fair to say that England contributed to their own downfall with the bat. Captain Alastair Cook was probably guilty of going for too much of an extravagant shot during the early part of the innings, while the dismissal of Matt Prior for just a single allowed Australia to target the final four England batsmen. Whatever happens today, you feel that the same mistakes cannot be made again if England are to avoid falling 1-0 behind in this series.
Stuart Broad was absent from the England bowling attack yesterday evening after being struck on the shoulder during his stint with the bat. The good news is that the pace bowler has passed a fitness test this morning, and due to the injury being from impact, rather than a muscle problem, Broad will be allowed to bowl from the start of the session, should Cook hand the ball to him.
We are less than 10 minutes away from the action getting underway at Nottingham. You get the feeling that the opening hour will go a long way to indicating how the rest of Thursday will go. England need a fast start to keep Steven Smith and Phil Hughes under pressure.
Before we get going, there has been a few interesting quotes from former England skipper Nasser Hussain, who believes that Ian Bell was the "chief culprit" of England's demise yesterday. Read the full story here.
The two teams are out, and we look all ready to go. There appears to be a boisterous crowd inside Trent Bridge today. Finn to start...
It's an indifferent start from the Middlesex man, who sends the ball down the leg side twice in his opening three deliveries, but the fourth is on the money, forcing Smith into a forward-defensive. However, the Australia batsman gets the score ticking over again with a pull for three.
James Anderson is on at the other end, and he immediately deliveries the ball on a full length to tempt Smith into a drive on the off side. It's a similar story for the rest of the over, and the Lancashire bowler records an early maiden.
Finn is struggling to find his line, and he gifts Australia four runs after bowling down the leg side to Hughes. The left-hander and Smith help themselves to a single each, before Finn ends the over in the same fashion as he started, with Hughes deflecting the ball to the boundary off his body.
Smith looks comfortable out there in the middle, and he moves to 43 with a quickly-run single. Hughes appears to be taking a more patient approach, but he lets loose with a perfectly-timed cut shot that flies past the point fielder.
I think we are starting to see how much the conditions played their part yesterday. There has been no swing this morning, and the pitch looks flat. After a couple of singles to start the over, Smith cuts the ball away for four after a poor delivery from Finn. He is just two away from the first fifty of the series.
Anderson offers little during the first half of the over, but Hughes latches onto just a little bit of width to drive the ball through the covers to bring the 100 up for Australia.
FIFTY! We have our first offering of spin of the day, with Graeme Swann coming into the attack, but he is welcomed to the action with a crashing drive from Smith, which brings up his fifty. The right-hander is looking to use his feet at the earliest opportunity, which brings him another single off the penultimate delivery.
WICKET! Smith (53) c Prior b Anderson
That's a huge breakthrough for England. Smith was looking increasingly confident at the crease, but he has fallen victim to Anderson, who found the edge. Brad Haddin is the new batsman, and he is immediately off the mark with a single into the leg side. A lot more onus will be placed on Hughes's shoulders now, and he responds with another cut shot that brings four more runs.
WICKET! Haddin (1) b Swann
Wow! I thought that we wasn't supposed to see any spin for the latter part of the Test? Swann has just found a huge amount of turn off his first delivery, which has caught Haddin by surprised and dislodged the bail. Peter Siddle is in, and he is fortunate to survive after edging the ball behind, but it proved too sharp a chance for Prior, with the ball crashing off his pad.
WICKET! Siddle (1) c Prior b Anderson
This is quite an incredible turnaround by England. There were no alarms for Australia during the opening half hour, but they have capitulated in the past 15 minutes. Anderson has started to move the ball through the air, and Siddle has no answer, edging the ball behind for Prior to take a fine one-handed catch.
DROP! Australia should be eight down! Anderson is motoring in at the moment, but after finding the edge of Mitchell Starc's bat, Swann has dropped a dolly at slip.
Darren leaves us at this point in the morning and I'm here to take you through the rest of the day. Let's hope my arrival doesn't stop the excitement at Trent Bridge. What does Hughes do now? Well, he has no option but to block out a maiden as Swann delivers an accurate over following his drop at second slip.
WICKET! STARC (0) C PRIOR B ANDERSON
Fantastic bowling once again from Anderson. There's just enough movement in the air to catch Starc's edge and Prior is left to take a routine catch. Five wickets for Anderson, he's claimed more Test victims at Trent Bridge than anyone else. Australia in big trouble here. James Pattinson comes to the crease.
Pattinson defends his first two balls before pushing Anderson through the covers for a couple of runs. The final delivery is a beauty but Pattinson reads the length well to execute a good leave. I just wonder whether it's time for Hughes to counter-attack.
Maybe Hughes shares my opinion as he misses with an ugly sweep. Huge appeal for lbw but Aleem Dar shakes his head and Cook decides against appealing. Good choice from the skipper. A leg-bye is taken and Pattinson comes on strike before surviving an equally vociferous lbw appeal.
WICKET! PATTINSON (2) LBW B SWANN
Third time lucky for Swann! Pattinson is struck on the front pad and Swann finally convinces Dar to raise his finger. The batsman reviews the decision but Hawkeye proves he was trapped plumb in front of the stumps. Superb from England. Time for drinks.
Ashton Agar walks out to the middle with his side in big trouble. The number 11 gets off the mark from his second ball with a single to deep cover.
Judging by his first-class record, Agar isn't the worst batsman you'll see come in as last man. Agar defends comfortably before clubbing the ball over Anderson's head for a single. Hughes takes advantage of some width to cut four through point. A single from the final ball of the over means the last top order batsman will keep the strike.
Swann begins a new over, licking his lips at the prospect of bowling at two left-handed Australians. The spinner displays his variations as he fires in a quicker ball before beating the outside edge with a wider one that drifts away at the last second. The most important fact is that Hughes does survive. It's a maiden and Australia still trail by 91 runs.
Agar gets off strike at the start of Anderson's new over. Hughes loses his form at the crease as he chase one outside off-stump. A miscued pull shot squirms into the leg-side but for just one run. Agar shows great timing to push the ball straight down the ground for four. Beautiful strike from the tail-end batsman.
Hughes beats Cook at point but picks out the fielder in the deep to just earn a single. Well, we've got a bit of talking point now. Prior is convinced he's stumped Agar and the umpires send the decision upstairs. It looks like the batsman didn't get his toe back but the third umpire gives him the benefit of the doubt. Close call but England might feel a little unlucky there. Agar quickly gets back to business as he drops to one knee and paddle-sweeps Swann through fine-leg for four.
Finn returns to give Anderson a break. Hughes takes a single to deep point to give Agar the strike early in the over. Agar attempts a big pull shot but he's not even close to making contact with the ball. A fuller delivery allows the 19-year-old to free his arms and drive through the off-side for another boundary. The strike is rotated again when Agar takes a single to fine-leg. Finn attempts to surprise Hughes with a bouncer but there's no support from the pitch and the batsman sits back to hammer the pull shot through mid-wicket for four. One more single makes it 11 from the over.
Swann settles on a brilliant length to Hughes, who defends well before edging the ball towards slip. The ball drops short of Trott, who does well to prevent a run from being scored. Excellent control from Swann. Maiden.
Finn seems eager to test Agar with the short ball but it's just not the right tactic on this pitch. Australia's number 11 is comfortable against the pace and he pulls three through the leg-side. Finn eventually decides to make use of the slips as he nips one past Hughes's outside edge. One run is added to deep point and Agar ensure that he keeps the strike with an easy single on the off-side.
Agar is eager to use his feet to Swann and he displays great confidence midway through the over to skip down the pitch to loft the spinner over long-off for six. Swann responds well to surprise Agar with a quicker ball but England's frustration continues.
Finn is too straight and Hughes takes advantage of the big gaps on the off-side to collect a run. Poor from Finn, who fires in a half-tracker to invite a pull shot from Agar. Four more to the surprise selection, he moves to 31 with two through mid-wicket.
Swann continues his pursuit of the 10th wicket. Hughes blocks early on before nudging a single through cover. Agar executes one of the more expansive drives you'll see today to beat extra cover and reach the boundary, bringing up the fifty partnership in the process. Swann responds by beating the outside edge but Australia continue to chip away at that deficit. The tourists trail by just 46 now.
Finn comes round the wicket to Hughes, who frustrates the bowler by sneaking a single early in the over. The Middlesex seamer continues with the same angle but once again he decides to deliver a short ball, which Agar heaves over square-leg for four more. You could forgive one short ball but that's just poor from Finn. Bairstow is unlucky in the deep as his valiant effort to prevent another boundary ends in disappointment. Brilliant counter-attack from Agar. Nine from the over.
Hughes is pushed back by a couple of quicker balls from Swann early in a new over. He may be a top-order batsman but Hughes seems to have no problem with playing a supporting role at the moment as he blocks out a maiden. Time for Broad maybe?
It's not Broad but there is a change as Cook throws the ball back to Anderson. The returning bowler decides it's better to go full to Agar, who clips the second ball of the over through mid-wicket for three. Hughes stands tall to punch two runs straight back past Anderson before adding another to deep mid-wicket. Agar moves a step closer to a half-century by sneaking a single on the leg-side. One more run makes it eight from the over.
Well, here's a great little fact for you. Agar, who is currently on 47, has broken the record for the highest score made by a number 11 on debut in Test cricket. An amazing start to his career.
Hughes shuffles across his crease to nudge a single into the leg-side. Swann does his best to tempt Agar to play the big shot that would bring up his half-century but the youngster resists, for now. If you're thinking the players should be off for lunch, you'd normally be right but an extra 30 minutes can be claimed when an innings is close to finishing.
Hughes once again hands the strike to Agar early in the over by taking a single to fine-leg. The record-breaking number 11 moves to 49 with a run just behind square on the leg-side. Hughes adds another to deep point. Anderson appeals optimistically for lbw but I think he knows the ball pitched outside leg-stump. FIFTY! Brilliant story on the second day of the Ashes. Agar, the 19-year-old number 11, reaches his half-century on debut with a couple of runs through third-man. Trent Bridge shows their appreciation for the youngster and rightly so, great effort.
Hughes moves closer to a milestone of his own as he nudges his 46th run to mid-on. Right, can someone tell Darren Lehmann to have a look at his batting order? Agar plays one of the best shots you'll see this summer as he launches a brilliant six over long-on. He adds two more with a good shot down the ground. Australia trail by just 14 runs. It's been a fascinating morning of Test cricket.
Hughes clips the ball to deep mid-wicket for a single. Anderson finds a good length to Agar, who's finally forced to defend, for two deliveries. A pull shot into the deep brings just a run. Some good communication allows Hughes to add two more to mid-wicket. FIFTY! The Australian supporters have another milestone to applaud as Hughes reaches fifty with a single. After suffering in the previous two Ashes series, that will be a big boost to the batsman.
Agar rejects a second run when Hughes flicks the ball through mid-wicket. Swann loses his length and Agar decides it's time to break another record. A brutal shot through the leg-side for four means Agar has now set a new record for the highest score by a number 11 playing for Australia. It just gets better. Agar rocks back to delicately cut Swann through third-man for four more. This young man is not a number 11.
Broad is finally brought into the attack with the scores now level. We were told he was fit, so I'm not sure why it's taken this long. The seamer starts with a good length to Hughes but the tourists move ahead when the batsman drills the ball through cover for four. That's also the century partnership between these two. Broad responds by catching the outside edge but Cook has removed second slip and Hughes collects four more. The lead is now 12 as Hughes walks down the pitch to power Broad behind point for another boundary.
Swann dips his hand into his bag of tricks in an attempt to get the better of Agar but there is no way through for the spinner. A thick edge through point brings a run and that's the only blemish on the over. Probably time for just one over before lunch.
LUNCH: Broad strives for the perfect length in the final over of the session but there's no joy for England's patched-up seamer. Just one single score. What an amazing morning of Test cricket.
It's Australia who will be eating their sandwiches with the biggest smiles on their face. An hour ago it looked like England would start their second innings with a comfortable lead. However, Agar has other ideas as he cruised to a brilliant half-century. He has 69 at lunch, Hughes is on 63. Test cricket, at it's best.
It's worth remembering that Anderson has figures of 5-70. Australia were 117-9. That was before Agar's heroics though. England must take this final wicket soon after lunch. Hughes and his partner have made batting look easy today.
If you want a cup of tea, I'd suggest you flick the kettle on now because the way this match is progressing, you can't afford to miss a ball.
Did England relax too early? The bowling late in that session, particularly from Finn, just wasn't good enough. You just won't get any reward for bowling short on this wicket.
Australia currently lead by 14 runs, which shouldn't worry England too much. The hosts will be disappointed but they know that Swann is likely to become a big factor as the next couple of days progresses.
England must regain the intensity they had earlier this morning. Australia just need to keep doing what they're doing and hope that they can make a few early breakthroughs with the ball later this afternoon.
Former England captain Michael Vaughan on Twitter: "Test Cricket is by far the best format...This morning was all the evidence you need..Outstanding drama... Ashton Agar take a bow... #Ashes."
Got your tea? Sitting in the living room copying Agar's shots? That must mean it's time to resume. We're just a few minutes away from cricket again.
Both sides are back out in the middle. It looks like we're ready to begin. Agar 69* Hughes 63* Anderson will bowl the first over of the session.
Agar starts the session by flicking a single to fine-leg. Anderson struggles to find the right line early in this over, conceding two through square-leg before Hughes flicks four to fine-leg. Two more runs added. Solid start for the tourists after lunch.
Agar continues to bat fluently with a Lara-like pull shot through the leg-side for four. Broad's frustration continues as he follows three dot balls by being whipped through mid-wicket for another boundary. One more run makes it nine from the over.
Agar collects two early in Anderson's over before displaying some flair with a punch through mid-on for four more. Australia's number 11 now has 86 from 83 balls.
England have generally bowled too short at these two. Broad is worked away for three singles early in the over. Hughes takes advantage of a fuller ball to drive four straight down the ground. Pietersen made the best possible effort at mid-off but it doesn't save him from Broad's stare.
Agar and Hughes trade singles before the latter slices the ball through third-man for a couple of runs. Anderson improves as the over progresses to push Hughes back deep in his crease. Can Agar really score a century?
Agar moves to 88 with a quick single to cover. Pietersen fields well at long-off to prevent a well-struck Hughes drive from reaching the boundary. The partnership is now worth 150. Hughes flicks another run off the hip before Broad surprises Agar with a good bouncer. Agar moves into the nineties in fortunate fashion as a lofted pull shot lands safely on the leg-side.
Another record is broken. The current partnership is the highest ever 10th-wickets stand in Test cricket. Agar is nine short of a century on debut.
Swann comes into the attack and immediately beats Agar's outside edge with a gorgeous delivery. It's a testing over for Agar and, dare I say it, the nerves are beginning to show. Swann find some big turn to beat the edge again but Agar survives. A thick inside edge brings a single. Hughes adds one more to steal the strike.
Broad comes round the wicket to the two left-handed batsmen. Hughes nudges a single into the leg-side and Agar pushes another run down the ground.
A thick edge races past Trott at slip and brings three runs to third-man for Agar, who now holds the record of the highest Test score by a number 11. Swann tests Hughes just outside off-stump but the technique looks good to me as he defends the remainder of the over.
Agar edges closer to one of the more memorable Test cricket moments as he pushes two into the off-side. Broad tempts the number 11 with a couple of shorter balls but he misses wit a pull and cut.
WICKET! AGAR (98) C SWANN B BROAD
Oh, dear. Memories of Tino Best last summer come rushing back as Agar misses out on an astonishing century. The 19-year-old hits the pull shot brilliantly but he picks out Swann in the deep. What an incredible innings from a very confident young man.
Agar will be very disappointed but he probably knows just how important his innings was as he walks off to a standing ovation. The number 11 and Hughes have guided Australia to a lead of 65. It's been a brilliant day at Trent Bridge and there's plenty more cricket to come.
The break doesn't last long. Australia will be full of confidence heading out to the middle. Cook and Root follow the tourists.
Pattinson will bowl the first over of the innings. England need a good start but conditions do seem to favour batting at this stage.
Pattinson starts the over with a no-ball before conceding a single to Cook through square-leg. Root sits deep in his crease to nudge a single into the off-side.
Starc shares the new ball with Pattinson. It's a good start for the left-arm seamer as he launches a big lbw appeal. Aleem Dar shakes his head but Clarke uses a review. Hawkeye shows that the ball may have clipped leg-stump but the decision stays with the umpire. It's a good start for the seamer, maiden.
Pattinson continues to Cook, who is eager to play the ball late against the swing. There's not much movement for the bowler but he's close to an edge when the hosting captain hangs a bat outside off-stump. Cook readjusts to see out a maiden.
Root looks his usual calm self at the crease as he shows off his defensive shots to the Australian visitors. Starc is very accurate though and he almost sneaks through Root's defence with a very good yorker. Maiden, again.
Cook gets off strike early in the over to break the run of dot balls. Pattinson is bowling with good pace early in this innings and forces Root on the back foot, where he's more than comfortable. Just one from the over.
Starc takes the ball away from Cook to catch the edge but the ball drops short of the slips. England's captain shuffles across the crease to nudge a run through square-leg. Root considers nibbling at one just outside off-stump but he wisely pulls his bat away. The Yorkshire ace misses a leg-side half-volley but Haddin can't collect the ball and England rush a single.
Root, who had scored just one from 24 balls, reaches the rope for the first time with four through third-man. Pattinson tightens his line following the boundary to keep it to four from the over.
Cook flicks a single off his pad at the beginning of the over.
WICKET! ROOT (5) C HADDIN B STARC
Australia make the vital breakthrough as Starc removes Root. The opener plays at a leg-side delivery and there's a sound as the ball makes its way through to Haddin. Aleem Dar raises the finger and despite looking surprised, Root chooses not to review. Trott in next.
WICKET! TROTT (0) LBW B STARC
What a moment! Starc delivers a beauty to Trott and there's a massive appeal for lbw. Mr Dar shakes his head but Clarke wastes no time in reviewing. Hotspot doesn't show an edge and despite Trott's disappointment, Starc has his second wicket.
TEA: Starc will be on a hat-trick when the players come back after tea. Trott really is disappointed with that decision. We didn't see a side-on angle with Hotspot, so maybe there was an inside edge.
There's no changing the decision now. England have 20 minutes to get themselves together. Cook (4*) will start the next session alongside Pietersen.
That's exactly the start Australia needed to make to the innings. Two wickets early on and the tourists still lead by 54 runs. The game is moving at a very quick rate. I wouldn't be surprised if we don't reach the fifth day.
It really has been an incredible day so far. England took control with a flurry of wickets this morning but Agar, who recorded the highest Test score by a number 11, guided Australia to a first-innings lead. However, the 19-year-old was denied a century on debut when he was caught by Swann for 98. Please don't tell me Test cricket is boring.
Pietersen will only play in one way. There's no chance of him changing his style in the final session but England really cannot afford to lose another wicket anytime soon. Steven Finn has been seen in his pads, so maybe he's preparing for a stint as nightwatchman.
Cook and Pietersen are back out in the middle. Two balls left in Starc's over and remember, he's on a hat-trick for the second time in the match.
It's a bit of a waste from Starc as he pushes one wide of Pietersen. He ends the over with a much better delivery but the new batsman survives.
Cook is agonisingly close to dragging the ball onto his own stumps when he miscues a pull shot but the captain has four runs instead. The England skipper plays the next delivery with very soft hands and he picks up four more through third-man. Much better end to the over from Pattinson but there's still eight scored.
Pietersen gets off the mark with a quick single at the start of Starc's new over. Cook rotates the strike again when the bowler goes too straight. Pietersen splits the fielders on the off-side but some good work restricts England's number four to one run. Starc's length is impressive, he looks far more threatening in this innings.
Pattinson finds some good movement in the air as he delivers two full balls to Pietersen early in the over. A similar delivery is pushed straight to the fielder at short mid-wicket. Pietersen finally settles against the full length as he drives straight down the ground for four runs. Just the boundary from the over.
Starc, with figures of 2-5, continues his spell. Cook defends well before flicking a slightly fuller delivery through square-leg for a single. Pietersen is as confident as ever as he tries to work the dangerous Starc through mid-wicket. There's no freedom for Pietersen though, just one from the over.
Agar comes into the attack for the first time. He'll be full of confidence following that 98, so it's time to make an impact with the ball. It's a very good start from the spinner and there's mutterings of an lbw appeal before the fielders realise Cook gets an inside edge on a good ball. Maiden over.
Starc is now choosing to push the ball across Pietersen in the hope that the batsman will be tempted into a loose drive. No luck for Australia though as Pietersen defends before nudging two through the covers from the final ball of the over.
Agar does get some good bounce due to his height. Cook is caught in two minds early in the over but he adjusts well to block off the back foot. A clip through mid-wicket brings Pietersen on strike. It's the old enemy for Pietersen, left-arm spin. He begins the challenge well though as he drops to one knee to sweep the young bowler away for four.
Cook sits deep in his crease to cut Starc through the covers for a couple of runs. A short ball is comfortably pulled away for two more. Starc then goes very full to the England skipper but Cook digs out the attempted yorker. The deficit is currently 27.
Pietersen misses out when he drills a full-toss straight back at Agar. The spinner oversteps the mark midway through the over and he's punished for the no-ball. Brilliant from Pietersen as he steers the ball between two fielders on the off-side to earn four runs.
Clarke decides it's time to turn to Siddle, who did most of the damage in the first innings with figures of 5-50. The seamer starts with a full length just outside off-stump but it looks like the natural swing has disappeared after 17 overs. No mistakes from the captain and he ends the over by sneaking a single on the leg-side.
Agar's spell comes to an end as Watson is given the ball by his captain. The seamer is always accurate and he's doing just enough with the ball to put some doubt in Cook's mind. The batsman is in no mood to give his wicket away though as he negotiates a maiden over.
Pietersen is at his best as he powers Siddle straight down the ground for four runs. Aleem Dar is a little unhappy with Siddle's follow-through but there's no official warning. Watson comes in at the shortest of mid-on positions but there's no chances for the tourists.
Watson is yet to be hit for a run but he gets himself into a mix-up as he drops the ball during his action. Cook looks far more confident around off-stump, compared to his scratchy knock in the first innings. Watson completes a maiden over.
Not much wrong with what England are doing at the moment. They needed to slow the game down a bit and this partnership is doing a good job of halting Australia's progress.
Pietersen does his best to find a single early in Siddle's over but he picks out the fielders at mid-off and mid-on, respectively. The seamer fires in a bouncer, not at great pace, but Pietersen leaves it anyway. Maiden over. It looks like a very good time to be batting.
Clarke continues to rotate his bowlers as Pattinson returns for a new spell. Good length from Pattinson, who starts the over full outside off-stump. The seamer returns with a maiden. Quiet period in the match. You're right, that's a silly thing to say.
Pietersen (21*) gets off strike at the beginning of the over. Australia are playing the patient game with Cook (20*) as Siddle settles on a good length just outside off-stump. No mistakes from Cook, who has that relaxed look on his face once again. England trail by 16.
Clarke should be pretty happy with his bowlers at the moment. Although there's not much going on, England aren't being given the opportunity to express themselves. Pattinson completes another maiden and it's time for a drinks break.
Siddle is your go-to man. No matter what the situation, he'll sprint in and bowl at the same pace all day long. It's another tidy over from the seamer, with just a single coming off a thick edge from Cook.
Pattinson is too short to Cook and the hosting skipper whips the ball off the hips for two runs through mid-wicket. A nudge into the leg-side brings another run. Classic Pietersen as he takes advantage of a full delivery to hammer four runs straight back past the bowler.
Clever bowling from Siddle and his patience nearly pays off. Cook leaves four deliveries outside off-stump before flirting with the fifth and breathing a sigh of relief when he realises he doesn't edge the ball. It's a maiden from Siddle.
Pietersen is targeting the gaps straight down the ground as Starc returns for a new spell. Nothing flashy about Pietersen's innings so far but it's been effective. Starc attempts to sneak through the gap with a yorker but the batsman digs the delivery out. Maiden over.
Maybe this could be a crucial period coming up. Agar is back into the attack. Will Pietersen be tempted to attack at this stage?
Cook remains watchful against the spinner and gets off strike in the middle of the over. Oh, bad luck for Agar. The spinner catches the edge but the ball travels quickly and Haddin can't take the catch. Pietersen piles on the misery by drilling the next delivery through the covers for four. An lbw appeal is rejected late in the over. We could be in for an intriguing battle from here.
Starc's threat isn't as high as it was before tea but that's mainly due to the age of the ball. It's a tidy over though, with Cook just adding a single through square-leg. England trail by just two.
Perfect shot from Cook to drive a fuller ball from Agar through the off-side for four runs. The spinner responds well to find some extra bounce and surprise Cook, who is fortunate not to get a glove or a bat on the ball. Smith does superbly at short mid-wicket to prevent any more runs from being scored. Good challenge for Agar.
Starc comes round the wicket to Pietersen, who has batted very sensibly since arriving at the crease. The seamer's pace is down but his accuracy is admirable. No poor deliveries means no runs for England. Maiden over.
Great control from Agar, who is beginning to settle into a nice rhythm. Cook wants to work everything onto the leg-side and he almost gets himself into trouble when a leading edge drops short of the bowler. It's another maiden from Australia.
Starc pleads with the umpire to give lbw but I'm afraid it's clear to the naked eye that the ball was missing leg-stump. Pietersen puts Australia through their paces as he tests the reactions of the fielders on the off-side. A leg-stump full-toss allows Pietersen to pick up a single from the final ball of the over. England lead by three.
Haddin shouts behind the stumps when Pietersen chips the ball into the air but the ball is perfectly guided through a gap at mid-wicket for three runs. Cook sits back when Agar drops one short and the opener cuts well to earn four through third-man. The England skipper then clips a single through square-leg before Pietersen is left to admire a delivery from Agar that almost sneaks through his defence.
Cook helps himself to a single early in Starc's over. Pietersen has now faced 81 balls for his 33 runs, which is very unlike England's number four but his knock has come at an important time. Australia continue to bowl tight lines. Just one from the over.
Cook is once again happy to hand the strike to his partner at the start of the over. Pietersen gets forward well to Agar to smother any turn the spinner might be able to find. A back-foot punch through the covers brings Pietersen a run.
Siddle returns to the attack as Australia look for a massive breakthrough just before the close of play. Clarke changes his field a few times in the over but his frequent alterations make no difference as Pietersen plays out a maiden.
Agar uses his variations in his over in an attempt to make life uncomfortable for Cook. Not too much encouragement for the spinner though, despite completing a maiden.
Pietersen has fought his attacking instincts well this evening but it won't matter unless he makes it to the close of play. Siddle continues to put great effort into every delivery but he's met by some textbook defensive strokes. Maiden over, again.
One last throw of the dice this evening for Clarke as Watson comes on for a new spell. The seamer goes very full early in the over but Cook shows good balance at the crease to stop the threat. You won't be surprised to hear it's a maiden. Probably just one over left in the day.
It doesn't matter what time of day it is, Pietersen can't resist taking on the short ball to pull a single into the deep. Cook goes about his business as usual, blocking out the remaining deliveries.
CLOSE OF PLAY: We've only seen two days of cricket but we've had enough entertainment to last us for most of the series. Cook ends unbeaten on 37 and Pietersen will begin tomorrow on 35.
Ashton Agar is undoubtedly the star of the day at Trent Bridge. His brilliant 98 as a number 11 wrestled back some of the control for Australia and ensured that this match is delicately poised heading into the third day.
England end the day with a lead of 15 and they'll want to bat sensibly, but positively, on Friday. Who wants to call a winner? I'll leave that to you.
Thanks for following our coverage today and make sure you return at 10.30am as this fascinating match continues. Goodbye.
