LONDON — Roger Federer wasn't about to let Jo-Wilfried Tsonga pull off another improbable comeback.
After a year that saw some uncharacteristic slip-ups from Federer in big matches, the Swiss star shrugged off a second-set letdown to beat Tsonga 6-3, 6-7 (6), 6-3 for a record sixth title in the ATP World Tour Finals.
"I know it's one of my greatest accomplishments," Federer said. "This definitely is an amazing finish again to the season. I've never finished so strong."
Federer was by far the most impressive player this whole week at the season-ending event for the top eight players in the world, where his three group-stage victories included his most comprehensive win ever over Rafael Nadal, beating the Spaniard 6-3, 6-0 on Tuesday.
But he looked in danger of faltering against Tsonga when he failed to serve out the match at 5-4 in the second set and then wasted a match point in the tiebreaker.
But Tsonga, who became the first player to rally from a two-set deficit to beat Federer in a Grand Slam tournament in this year's Wimbledon quarterfinals, couldn't pull off another surprise this time.
Playing in his 100th career final, Federer broke for a 5-3 lead in the decider and served out the match to love, sealing his 70th career title with an easy volley.