Federer makes winning start

Defending champion Roger Federer kicked off the singles action at the Barclays ATP World Tour Finals in London with a 6-2 2-6 6-4 victory over Jo-Wilfried Tsonga.

The fourth seed cruised through the opening set at a packed O2 Arena, but Tsonga hit back when Federer's level dropped in the second and the result looked in doubt until the Swiss star broke to edge a tight decider.

The 30-year-old went into the tournament as the man to beat after back-to-back titles in Basle and Paris, where he beat Tsonga in the final to remain unbeaten since the US Open.

Federer had won both their most recent meetings and did not take long to move ahead, breaking in the fourth game after his opponent had let him off the hook in the previous game with a woeful miss. Another break to love gave Federer, a fairly uninspiring set in 21 minutes, both men taking their time to adjust to the relatively slow pace of the court.

But Tsonga then benefited from a series of Federer errors in the third game of the second set to break. That gave the former Australian Open finalist the lift he needed and he began to play much better, using his brutal power to rush his opponent.

His fearsome forehand was becoming a real feature of the match and he used it to great effect to force another break to move 5-2 ahead, before clinching the set when Federer netted a backhand.

The Frenchman was the first to face a break point in the fifth game, which he saved with a pinpoint forehand, but the outcome remained on a knife-edge. Rafael Nadal, in action later in the other Group B opener against Mardy Fish, arrived courtside for a glimpse of the action, but no sooner had he done so than Tsonga cracked.

An easy volley dumped into the net was followed by a double-fault, and when Federer creamed a winner down the line he had three match points, taking the second with a backhand placed neatly behind his opponent.

Federer admitted his shock Wimbledon loss to Tsonga had been on his mind when the Frenchman began to turn things around in the second set.

The 30-year-old said: "It's very hard to get into any sort of rhythm against him from the baseline because he's a very good one-two puncher, which he proved over four and a half sets against me at Wimbledon. Today I had flashes of that match because I didn't have much of a chance for a while on his serve. You just try your best."