Afternoon all! We're an hour away from kickoff at Wembley and there's big team news coming from the capital already...
CITY XI: Pantilimon, Zabaleta, Clichy, Kompany, Nastasic, Barry, Milner, Y Toure, Nasri, Aguero, Tevez
Anyone missing for you? Yes, David Silva isn't there but surely the biggest omission is that of goalkeeper Joe Hart.
The reason for this is that Costel Pantilimon has been City's goalkeeper in the
FA Cup all season long and Mancini has stuck with the giant stopper.
In fact, the Romanian is the tallest player in the Premier League at 6'8".
CHELSEA XI: Cech; Azpilicueta, Ivanovic, Luiz, Bertrand; Mikel Ramires; Mata, Oscar, Hazard; Ba
The Blues' lineup reaches us a little later but here it is and it's predominantly as expected from Benitez, with Oscar,
Juan Mata and
Eden Hazard all playing behind
Demba Ba, who returns to the XI after having to miss the midweek trip to Russia in the Europa League.
It is somewhat surprising to see no John Terry or Frank Lampard in the Chelsea side though.
SUBS: And here are the two benches this afternoon:
Chelsea: Turnbull, Terry, Ake, Lampard, Benayoun, Moses, Torres
City: Hart, Kolo Toure, Lescott, Kolarov, Garcia, Sinclair, Dzeko
Both Terry and Lampard are on the bench for the West London side then. Moses and Torres are the other standout names in the dugout for the Blues while City can bring on the likes of Scott Sinclair, Edin Dzeko and Aleksandar Kolarov.
Now that we know the teams, let's briefly round up what's going on elsewhere, especially in the Premier League.
Right now they're 10 minutes into the second half at the Britannia where it's Stoke 0-1 Man Utd. Michael Carrick scored the goal in the fourth minute and you can follow the remainder with Barney Corkhill by clicking here.
The biggest news of the day so far though comes from the North East where Sunderland hammered arch rivals Newcastle 3-0, at St James' Park! Paolo Di Canio's celebrations were simply brilliant and you can find
our match report on that one here.
Anyway, back to our feature match on this page - Chelsea vs. City. These two may not be having it all their own way in the league this season but let's not forget, they are the reigning European and Premier League champions.
In the two matches in the league this year City have taken four points by earning a
goalless draw at Stamford Bridge before a
2-0 win at the Etihad in February.
UPDATE: United are edging ever closer to the league title as
Robin van Persie breaks his recent scoring duck by netting a penalty at Stoke to make it 2-0.
Chelsea and City have actually faced each other three times this season including the season curtain-raiser of the Community Shield. On that day back in August it was City again who claimed the silverware by winning 3-2 at Villa Park.
HOW THEY GOT HERE: Let's take a closer look at how Chelsea and City made it to the semi-final stage of this famous competition.
Chelsea beat Southampton 5-1 in January before struggling past League One side Brentford after a replay. Next up was a victory at Middlesbrough before the quarter-final victory over Manchester United. That one also required a replay.
The route to the last four has been much simpler for City. They are yet to concede a goal in this year's competition in their victories over Watford, Stoke, Leeds and Barnsley.
REFEREE WATCH: Today's man in charge is Chris Foy.
A lot has happened at Chelsea over the past year and one thing was an FA Cup triumph over Liverpool. The Blues have a tremendous record in this competition recently, having won it in five of the last seven years.
PREDICTION! It's not long until kickoff now and time for my thoughts on the match. City will be favourites but I just fancy Chelsea and can see the Blues nicking it. Hazard to score the winner. You heard it here first.
The two sides are ready and waiting in the tunnel. There's some friendly handshakes between Serbian teammates Nastasic and Ivanovic.
UPDATE: The full-time whistle goes at the Britannia and it's an easy 2-0 win for United as they edge ever closer to yet another league title.
Read our match report here.
Out they come to a noisy and soon-to-be packed out Wembley.
City are the team in home colours while Chelsea are in their changed strip of black with yellow details.
KICKOFF! Foy blows his whistle for the first time and City get us underway.
Here's an impressive stat from @OptaJoe on Twitter: "7 - Chelsea have won all seven FA Cup games that they have played at the new Wembley. Manor."
SIDE-NETTING! First effort of the match comes from the left boot of Aguero after a surging run from Toure. The Argentine can only find the side-netting of Cech's near post.
SAVE! It's all City at the moment as Nasri's corner is cleared but then fired back in by Barry. Toure deflects it goalwards and then Aguero instinctively flicks it as well and Cech does well to tip it wide.
It's been an end-to-end opening to this game, brilliant stuff. Chelsea can definitely threaten on the counter if City continue to pile bodies forward.
SAVE! Oh this is sublime interplay between Tevez and Barry. Tevez takes a shot from a tight angle after Cech seemed to have left a bit of a gap. The Blues' keeper won't be beaten there though and Chelsea survive again.
City continue to dominate possession but their latest attack comes to an end as Milner horribly overhits his cross from the right. Chelsea have to start pressing City and also hold the ball much, much better.
Zabaleta avoids a yellow card despite hauling down Oscar, who had nutmegged him on the left touchline. Another foul like that and the Argentine will definitely go in the book.
The pace of the game has definitely slowed down after that electric start. Chelsea appear more than happy to let City have the ball in front of them.
GREAT BLOCK! Fabulous ball over the top from Kompany to Aguero and it looks like the Argentinian will have an easy shot but Ivanovic does superbly to get back and make the block.
Tevez is next to see a shot blocked before Chelsea finally get out of their half and Ba wins a free kick on the right touchline. Chance for Mata to swing it in.
OFF THE LINE! The Spaniard's delivery is bundled clear but only to Hazard and he hits a volley into the ground that goes over everybody apart from Kompany who is there on the line to head it out.
YELLOW! Barry is the first player to go into the book after a nasty lunge on Ramires. The Brazilian is down injured for quite a while but it looks like he'll be OK to continue.
Mikel tries to find Ba with a quick free kick over the top and it's almost perfect for the Senegalese frontman but he can't quite bring it down.
It's been a much better 10 minutes from Chelsea and they're now the team on top as we enter the final quarter of an hour of the first half.
One player that has impressed so far is City centre-back Matija Nastasic. He's had a phenomenally consistent debut season.
GOAL! Chelsea 0-1 City (Nasri)
GOAL! Chelsea 0-1 City (Nasri)
It's a bit fortunate but City have the lead. Toure with another driving run into the final third and his pass inside finds Aguero in loads of room and he lays it off for Nasri. Weirdly, the Frenchman decides not to shoot but his pass is blocked and it falls back for him to finally apply the finish from just a few yards.
The City fans are celebrating wildly inside Wembley with their now-trademark 'Poznan' celebration. Can Chelsea get back in it before the break?
SHOT! It's a good effort from Mata but never looked like sneaking inside the far post. Oscar laid it off to the Spaniard and he struck it first time but it was curling the wrong way.
CHANCE! It's almost two for City as Toure threads Nasri in down the right and he in turn cuts it back for Tevez. The number 32 lays it on for Aguero and a bit of penalty-box pinball then leaves Milner with a free shot but he actually hits an offside Aguero and Chelsea survive.
The play continues to sweep from end to end as Oscar sends over a great cross but it's just too far ahead of the two black shirts in the area.
YELLOW! Toure is the second City player to see yellow for cynically hacking down Mikel after a clever turn from the Nigerian.
HALF-TIME: Chelsea 0-1 City
City almost had a second right before the break as five blue shirts streamed away on the break. However, Milner's cutback was parried out by Cech and Kompany contrived to miss the rebound. Big let-off for Chelsea.
If you've only just joined us and want a brief round-up of the opening 45,
read our HT report here.
I'm surprised at just how open the match has been so far. The stats heavily favour City as they have had 69% of possession and eight shots to Chelsea's two. They also got six of those eight on target.
Chelsea have more than enough quality to get back in it and I'd be amazed if this one stays 1-0 in 45 minutes' time.
The black shirts of Chelsea are ready and waiting in the middle. Still no sign of City.
Finally the light blue shirts trot out. Neither manager has made a change.
YELLOW! Doesn't take long for Ramires to go into the book.
GOAL! Chelsea 0-2 City (Aguero)
That was quick! City work the ball out to the right and Aguero peels off Ivanovic to head home Barry's flighted cross in off the far post. Fine, fine header and maybe game over?
Great feet from Nasri gets him past Azpilicueta and he then looks to reverse it through to Milner but the Englishman is well tracked and seen off by Luiz.
CHANCE! City should have put this one to bed. Toure anticipates Mata's feint inside and suddenly the Ivorian is breaking upfield with Aguero one side, Tevez the other. Chelsea only have two men back but Yaya's pass is behind Tevez before his pass to Aguero is intercepted by Mata, who did well to track back.
Huge roar from the City fans as Aguero keeps the ball in ahead of Ivanovic and then wins a throw-in off the Serbian. Aguero is so important for City when he's in this kind of form.
Oscar's shot is well struck but blocked and it looks like the looping ball may fall for Ba but Kompany does excellently to arch his back and head it clear.
Mata has the chance to curl in a free kick after Zabaleta's block on Luiz but it's a pretty weak delivery from the number 10 and Pantilimon catches comfortably.
Benitez summons Torres from his warm-up and puts his arm around the Spaniard before issuing instructions. We'll see the number nine shortly.
Hazard has had a very quiet game and it doesn't get much better as he smashes an effort miles over the bar.
CHANCE! Almost a real chance for Chelsea as Hazard clips over a clever little cross for Ramires but his header is very weak. Torres now waiting on the touchline to come on. Will Benitez go for two up front or take off Ba?
CHELSEA SUB: It's Mikel who comes off for Torres. Bold from Benitez.
GOAL! Chelsea 1-2 City (Ba)
It's not an instant impact from Torres but either way Chelsea score straight from the restart. A long ball over the top manages to find its way to Ba and he finishes off the post with an overhead volley. Tremendous finish.
CHANCE! Chelsea are right back in this of course and they almost equalise as Hazard breezes past Nastasic before Mata picks it up and tries to round Pantilimon. The keeper does very well to claw it out as Mata tries to round him.
SAVE! City are all over the place! It's Hazard again who creates as he outmuscles Clichy on the touchline and pulls it back for Ba who smashes goalwards but it's straight at Pantilimon who does well to save.
CITY SUB: First change of the match for Mancini and it's a defensive one as he takes off Tevez for Javi Garcia. City should now outnumber Chelsea in midfield.
All the noise from the Chelsea boys now but City will be very dangerous on the break with the pace of players like Yaya and Sergio.
Chelsea have a free kick about 30 yards out as Hazard is brought down. The Belgian stays down to receive some treatment but should be fine to carry on.
JUST WIDE! Luiz steps up and slaps the ball up and over the wall with the inside of his boot. Pantilimon knows where it's going though and sees it wide.
Toure has got crazy amounts of energy and he bursts into the area before shooting off-balance. He was tripped by Oscar and I'm surprised Foy didn't award a free kick for the contact outside the area.
LUCKY BOY! How is Aguero still on the pitch? He has just jumped two footed on Luiz. A really disgusting challenge, I have no idea how Foy has not seen that. Retrospective action should be taken by the FA.
Mata clips a delightful ball over the top and it looks for all the world that Torres might poke home but he can't quite catch up with it and Pantilimon gathers.
This time it's Aguero who is fouled nastily by Torres's studs on his ankle. Nowhere near as bad as his challenge on Luiz moments earlier though.
CITY SUB: Another defensive change from Mancini as he takes off opening goalscorer Nasri for Joleon Lescott.
Torres wants a penalty as he gets wrong side of Kompany but can't get a shot away as the Belgian tussles back. Correct call from Foy this time.
FOUR minutes added on at the end.
Toure continues to be immense as he brushes off Azpilicueta and pulls it back for Aguero but the Argentinian trips over his own feet and Chelsea have three minutes to find an equaliser.
Big groan from the Chelsea fans as Bertrand floats over a naff cross that the giant Pantilimon gets to.
SHOT! Hazard fancies playing the hero as he lets fly from 30-odd yards but it's a wild effort that swerves wide.
Into the final minute and the City fans are begging for the final whistle.
FULL-TIME: Chelsea 1-2 City
A fantastic game of football at Wembley between two of the Premier League's top sides. It's City who triumph, just, and they've knocked out defending champions Chelsea.
If you've only just joined us and want a summary of the game then
click here for Rob Summerscale's match report.
City will now face Wigan Athletic in next month's final on May 11. They will go into it as heavy favourites and surely they're on for a second FA Cup in three years.
Anyway, that's it from our live coverage. Make sure you stick around on site for analysis and reaction on a cracking semi-final. We've also got live coverage on the final round of The Masters starting soon so look out for that. Until next time, good evening.