Live Commentary: Tomas Berdych vs. Stanislas Wawrinka - as it happened

Hello, and welcome to Sports Mole's live coverage of the ATP World Tour Finals match between Tomas Berdych and Stanislas Wawrinka.

There may be no Andy Murray in London this week, but this tournament still promises to be a dazzling spectacle. The two players are currently making their way out to a packed 02 Arena.

Before we get started, let me remind of how this tournament works. The eight qualifiers have been drawn into two groups of four players. The top two from each group will then compete in the semi-finals before the final takes place next Monday evening.

Stanislas Wawrinka has won the toss, and he will serve first on his ATP World Tour Finals debut.

Today's encounter will be the 13th time that these two players have met as a professional. Wawrinka leads that head-to-head 7-5, and the Swiss number also won their last match earlier this year at the US Open.

Berdych and Wawrinka are joined in their group by Rafael Nadal and David Ferrer, and that puts extra importance on securing an opening-match victory this afternoon.

Two players are ready, and it will be Wawrinka to get us underway.

Nerves? What nerves? Wawrinka plays the perfect game on his first appearance at this tournament. Three first serves aren't returned by Berdych, while Wawrinka shows off his power from the baseline with a excellent forehand down the line.

Berdych tamely nets the opening point on serve, but like Wawrinka, he is quick to display his raw power with three serves that the Swiss can't handle. A weak second serve is given the treatment by Wawrinka, but a fourth huge serve seals the game.

Blimey, there is little tact in Wawrinka's game right now. He reaches 40-0 with an ace down the middle, before he lets rip with his trademark backhand, and Berdych can only float the ball out. We've hardly had a rally in this match so far.

It's becoming quickly apparent as to why Wawrinka has got the better of Berdych this year. The Swiss player is wasting no time in moving Berdych about at the back of the court, and another blistering forehand winner takes him to 0-15. Berdych responds impressively, before throwing in a double fault to make it 30-30. However, when the fifth seed gets his first serve in, it isn't coming back with much on it, and that helps him level the set.

This really is an astonishing start on serve by Wawrinka. He sweeps to 40-0 with another ace, and although he commits a double fault, he replies with an easy conversion from Berdych's return to regain the advantage.

BREAK! Is this an opening for Wawrinka? Berdych twice goes long and the Swiss number two has 15-30. Wawrinka makes a forehand error, but Berdych gifts him break point with another double fault. The Czech player has the chance to gain advantage in the next rally, but he sends the ball wide, and Wawrinka seals the break.

Berdych replies by forcing Wawrinka into an error at the net, but Wawrinka has looked so dominant on his serve, and that continues for the remainder of the game. He is mixing up his play superbly, and although he hooks a forehand wide, he moves one game away from the set with another thunderous first serve.

Wawrinka continues with his aggression from the baseline, but his timing is a little off during this game and Berdych quickly moves into a 40-0 lead. The Czech player throws in another double fault, but he forces Wawrinka to serve for the first set.

SET! The Swiss player eases into a 30-0 lead, but I think Berdych has had enough. He drills a booming forehand winner past opponent, but it has little effect on Wawrinka, who responds with a winner of his own for two set points. However, he marginally misses the line three times in succession and out of nowhere, Berdych has a break point! He goes for too much with a backhand to quickly lose the opportunity, but Wawrinka wastes a third set point after netting a forehand. A fourth opening goes by when Berdych gets the better of a net exchange, but he finally wins the set at the fifth time of asking when his opponent shanks a return.

Berdych starts the second set with his first ace of the match, before Wawrinka tries to be too precise with a drop shot, and the ball fails to reach the net. Berdych misfires with a forehand, but he gets on the board in the second with an easy put-away at the net.

Wawrinka starts the game a little wildly by driving a forehand long of the baseline, but he soon moves 30-15 ahead. Another forehand goes long, but a Berdych mistake and a sublime backhand winner wins the game for the Swiss.

Berdych has began this set more composed than the first, but there's nothing that he can do when Wawrinka sneaks in to direct a backhand volley into the corner. The fifth seed looks in control of the game, but Wawrinka fires his backhand into the corner and we are at deuce. Berdych then throws in his fourth double fault, but he survives the break point when his opponent goes long, and eventually escapes with a 137mph ace.

Wawrinka catches the back of the line with a forehand, but Berdych has an opening at 15-30 when the Swiss can't handle the Czech player's power. Berdych fails to capitalise on a poor second serve, but he has break point when Wawrinka goes long. However, he has looked extremely edgy when granted with an opportunity, and Wawrinka holds serve.

Good stuff from Berdych, who converts a backhand volley with plenty of confidence to go 40-0 up, before Wawrinka shows incredible touch with a drop shot. The Czech player keeps his composure though, blasting down a serve that Wawrinka floats over the baseline.

Wawrinka produces an equally efficient game to hold to love, making it 3-3 by sending a forehand winner flying past Berdych. We are getting to a crucial part in the match.

There's simply nothing being given away on serve at the moment. Berdych is getting into a groove on his serve, and if this continues the way it is, we are looking odds-on for a tie-break.

Hmmm, what was I saying? Berdych gets the better of a lengthy rally to move 0-30 ahead. Wow...Wawrinka then shanks the easiest of conversions at the net to gift Berdych three break points. Berdych goes wide on the first with a return, while the second is saved with an ace. Can Wawrinka save the third? Of course he can...with another ace out wide. Quality from the Swiss. Berdych misses yet again, and Wawrinka reels off five points in a row with a cross-court backhand. What a recovery!

Did the momentum swing during that game? Berdych goes 30-0 up, but Wawrinka plays a delightful top-spin forehand to reduce the deficit. Berdych then nets tamely, and it's 30-30 - this is crucial. Unbelievable - the rally comes to a halt after an immediate correction from the line judge. We try again, and Berdych moves to game point with a fine serve down the middle, but Wawrinka hangs tough. It only delays Wawrinka being forced to serve to stay in the set though, as the Swiss goes long after being forced onto the back foot.

Another ace from Wawrinka takes him to 30-0, but he goes for too much with a forehand and Berdych has a sniff on a chance. It doesn't last long though, and Wawrinka makes it 5-5 with his second ace of the game.

Wawrinka lets out a roar after getting the better of a long exchange, but after a delay because of an advertising issue, he sends a shot long. Berdych edges ahead with a one-two off his serve, and he has two game points after a backhand slice from Wawrinka goes into the tramlines. Strangely, the backhand of the Swiss misfires again, and for a second time, he must serve to remain in the set.

It's a mixed bag from Berdych, who does well to take the first point, but lets himself down by floating the ball long. Wawrinka falls 15-30 behind, but his serve, which has been reliable so far, gets him out of immediate trouble. That's abysmal from Berdych, who makes another glaring error from the baseline, and we are heading into a tie-break after the most delightful of backhand drop-volleys from Wawrinka.

First blood to the Czech player, who thunders a serve down the middle, and he has the mini-break after finding his range with his forehand. Disaster for Wawrinka, who misses an easy conversion on his backhand side, and Berdych is 3-0 up. An ace out wide extends that advantage, before a dismal forehand from Wawrinka finds the net. What has happened to Wawrinka? He miscues a backhand and this set is as good as over.

Berdych has six set points, but he only needs one. The fifth seed steps in to drive a volley into the corner, and we are heading into a decider.

It's important for Wawrinka to put the last 10 minutes behind him, and he goes some way to doing so by holding to love in little over a minute.

Berdych powers his way to 30-0, before weakly sending a forehand into the net. We've seen little in terms of long rallies in this match, but Wawrinka wins this one to have Berdych in trouble at 30-30. Berdych earns game point with an ace, but he gives it away with a double fault. That's been the story of his performance so far. Wawrinka earns the first break point of this final set with a backhand winner, but it's saved by an ace, and a second one soon follows. Berdych eventually comes through the game.

Super hold from Wawrinka. A forehand winner is followed by two aces from Wawrinka, and the game is won when Berdych hits the ball over the baseline.

BREAK! We tick over the two-hour mark for the match, and we are at 15-15 in this game after a terribly weak forehand from Berdych hits the net. He then misfires with a backhand and Wawrinka has an opening. A fantastic second serve makes it 30-30, but Berdych is fortunate when a baseline shot clips the top of the net and the line. Another mistake takes the score to deuce, and a double fault from Berdych - his seventh of the match - gives break point to Wawrinka. He finds the first serve, but Wawrinka shows superb grit to turn the tables in the rally and force the mistake.

Wawrinka is fired up now. A forehand winner takes the Swiss to 30-0, and game point is brought up with a shot down the line. The momentum is well and truly with Wawrinka now, and the game is sealed with a drop shot. But the trainer is on for the seventh seed...

Berdych attempts to force the issue, but Wawrinka passes him down the line. I guess that means he is alright. Berdych wins two points in a row, but an eighth double fault makes it 30-30. That's a lot for a three-set match. However, an ace and a Wawrinka mistake keeps him in contention in the match.

How lucky is that? Wawrinka clips the top of the net and the ball drops just over to win the opening point, before Berdych misses the baseline twice in a row. The Czech player looks agitated after sending a return long, and Wawrinka is a game away from victory.

This is a must-win game for Berdych, and a 15th ace and a forehand into the net from Wawrinka help him to 40-0. Wawrinka pulls a point back, but a over-hit return reduces the score to 5-3. Wawrinka will serve for the match.

I've lost count of the number of times Berdych has sent baseline shots long of the baseline this afternoon, and he does so again at the start of the game. It's Wawrinka's turn to do so on the next point, but he redeems himself with a solid forehand down the line. He's two points away from the win, and it stays that way when he nets from the baseline. 30-30 - which way will it go? It's MATCH POINT to Wawrinka after Berdych can't return a second serve. And that's your lot. Berdych goes wide, and Wawrinka wins on his ATP World Tour Finals debut.

Stanislas Wawrinka marks his debut at the ATP World Tour Finals with a three-set victory over Tomas Berdych. It was a mixed bag from both players, but overall, it would be hard to dispute that the seventh seed deserved the win.

Tomas Berdych will be mightily disappointed with his display, and the amount of unforced errors he made during that contest. He will need to improve ahead of his next match against Rafael Nadal or David Ferrer.

That will be all from Sports Mole for this match, but please join us again for the night session later today, when Juan Martin del Potro takes on Richard Gasquet. Goodbye for now.