Roger Federer started his bid for a record sixth title at the ATP World Tour Finals with a 6-2, 2-6, 6-4 victory over France's Jo-Wilfried Tsonga on Sunday.
Federer's triumph here at London's 02 Arena 12 months ago moved him level with Pete Sampras and Ivan Lendl on five titles in the end of season finale and he is determined to successfully defend his crown after a frustrating campaign.
The 30-year-old, down to fourth in the world rankings, will finish the year without a Grand Slam title for the first time since 2002, but he arrived for 2011's concluding tournament in good form after back to back titles in Basel and Paris.
Although he gave a slightly erratic performance to kick off his 10th successive Tour Finals appearance, he has now won 13 matches in a row and 18 of his past 19 and his rivals among the world's top eight players will be rightly wary of Federer in this kind of mood.
"Jo-Wilfried served well in the second set and it was hard to control the rallies at the baseline," Federer said. "But I think this is the best I've played all year. It helped that I had some good time off before playing great at Basel and Paris." Tsonga added: "I think he was a bit surprised because I played so bad in the first set, then I played correctly in the second, but it's always difficult because he's really quick.
"Sometimes you think you will get the point but Roger is still there. That's why it's tough to play against him."
Federer suffered arguably the most stunning meltdown of his career when he last met Tsonga in London in the Wimbledon quarter-finals earlier this year. For the first time in a Grand Slam the Swiss star was beaten after holding a two set lead.
But he was finally back to his dominant best a week ago in the Paris Masters, which he won by defeating Tsonga in the final for his second victory over the French number one since that loss at the All England Club.
Federer, who had former Arsenal star Thierry Henry sitting in his box at courtside, picked up where he left off in Paris and took the first set here in emphatic fashion.
Tsonga didn't help his cause with two woefully mistimed forehands to present Fededer with the first break in the fourth game. Federer never looked likely to relinquish that advantage and he wrapped up the set with another break after Tsonga double-faulted at 0-30 and then netted a half-volley.