Good afternoon and welcome to live coverage of Roger Federer against Robin Soderling in their final Group B match at the ATP World Tour Finals.

GAME, SET AND MATCH FEDERER! A drop shot is enough to bring up two break points and he rounds off the match with another winner. Federer through to the last four. Soderling needs Ferrer to beat Andy Murray if he is to stay alive in the tournament. Looks unlikely, but where there is life there is hope. Federer just too good in one hour and 28 minutes.

BREAK TO FEDERER! A lovely rally at 30-30 before Federer finally turns the screw. A winning forehand across court from deep brings up the break before he plays a lovely passing shot that his opponent can't return. Surely that is going to the decisive moment in his match.

No breaks of serve in this set. Diego Maradona watching this one today in what seems to be an extended trip to London for Argentina's 1986 World Cup winner. Both men enjoying some success on serve. Soderling serving again after taking two points off Federer on his serve. Any mistake now will surely tilt the match in the Swiss player's favour.

Soderling is nothing if not a fighter. He is really being asked some questions by his opponent as that game meanders to 30-30. Federer looks poised to pounce, but Soldering displays his mettle to swat away a forehand for a key winner to pocket the game. We are level at 3-3.

A love game from Federer to apply the pressure to his opponent. Soderling has barely had time to regroup from the previous game and he is serving again.

Chances for Federer to break in the fourth game of the second set, but Soderling resists the charge of Federer to hold. Some really long rallies in that game, but the Swede claims the game when Federer clubs a backhand into the net.

Soderling needs to win this match, and hope that tonight's resuilt between Murray and Ferrer falls in favour of him. The way Federer is playing, that looks like being a big ask. Another accomplished service game from Federer sees him edge 2-1 ahead. Games continue on serve.

Soderling really finding some bite on his service game. The Swedish player has thrown down eight aces to nine by his opponent, and is winning 88% of his points on first serve. He levels up in the second game of the second set.

Soderling off to a quick start in the second set. Brings up two break points, but is unlucky when an attempted winner down the line drops wide of the target. He thought he'd got it, but the review falls in favour of Federer. Federer sees it out. A bit fortunate to get out of that one unscathed.

SET TO FEDERER! Federer claims the first mini-break of the breaker before collecting the next two points for a 5-2 lead. Soderling reduces his arrears to 5-3 before a wonderful agile overhead winner is enough to see him bring the score to 5-4. Federer throws down an ace to move 6-4 ahead before the Swiss catches the net with an attempted winner. The retrieve is only temporary as a Federer backhand drops in after Soderling elects to leave it. Federer squeezes through 7-5.

Federer's timing begins to creak ever so slightly. He is forced to 30-30 before Soderling pushes a looping forehand wide from the back of the court. Chance missed. A fourth ace of the match from Federer is enough to force the first set to a tie-break. Soderling to serve in the opening point of the breaker.

Solderling pumping his fist. He is in the pink in his yellow top. This one looks like it could swing either way now as Soderling produces a superb game to love. For the second time in the set, Federer must hold serve to keep the set alive.

Federer needs to win the set to be sure of winning the group assuming that Murray downs Ferrer later on this evening. A better service game from the artful Roger as he drops only one point in levelling matters. One back hand winner down the line was absolutely magnificent from Federer.

A third straight game to Soderling, and that was pretty impressive. Seems to be taking a bit of his groundstrokes and that is working for him. Soderling now up to six aces in the match as his recovery begins to gather pace. Federer serves to stay in the set.

BREAK TO SODERLING! First signs of a flaw or two in Federer's game as the world number two makes a few unforced errors to hand the break back to the Swedish player. Soderling happy to stay in the points and that seems to be working for him. Federer knocks a forehand long and we are back on serve.

Soderling has not given up the ghost. Just has to hang in there, and hope for his opponent to drop down a gear or two. Has been given little chance to impress himself upon the great Federer, but he does well to hold serve. Possibly his best service game of the match in that last one.

Federer seems to have the ball on a piece of string after the opening 22 minutes of the match. Working Soderling around the court, with one little disguised drop shot proving to be a winner tucked away to the back of the court with Soderling set to bound to the net. No hint of a break in that game.

No problems for Soderling in that game, but he remains a break of serve down in this set. Soderling only hitting the mark with 44% of his first serves and winning only 40% of the points on second serve. Will need to improve those stats.

Just what the doctor ordered for Federer as he cements his break with a love game. The Swiss master continues his regal form of these group stages. Looks unruffled and carrying out his plans to precision, a bit like the Federer we know.

BREAK TO FEDERER! Federer dominates meetings between this pair. He leads 14-1 in the head-to-heads, losing only in the quarter-finals of the French Open earlier this year. Soderling is forced to deuce in his next service game as Federer begins to find his range. The Swedish player wallops a forehand into the net, and Federer has a break point. Federer hammers a backhand low over the net, but Soderling knocks a tricky volley wide and there is the first break of the match.