|Federer was the last remaining top-four player in the tournament [GALLO/GETTY]
Roger Federer became the first player to win the ATP World Tour Finals six times after weathering a storming fightback by Jo-Wilfried Tsonga to retain his title with a 6-3 6-7 6-3 victory at London’s O2 arena on Sunday.
The 30-year-old, playing in the title match of the tournament for the seventh time in 10 years and his 100th Tour final, faltered when serving for the match at 5-4 in the second set and let a match point slip in the tiebreak.
Powerhouse Tsonga threw everything at Federer in the deciding set but he dropped serve at 3-4 and this time there was no escape for the crowd-pleasing Frenchman as the Swiss completed victory in two hours 18 minutes.
"I couldn't be more happy and I couldn't be more exhausted because Jo sucked all the last energy out of me today," Federer said on court after sealing the $1.63 million jackpot for going through the tournament undefeated.
On another record-breaking day for the 16-times grand slam champion, Federer gained the distinction of being the oldest player to win the season-ender since Ilie Nastase in 1975.
Despite not winning a grand slam title in a year for the first time since 2002, he also made sure he ended the season on a high with a 17-match winning streak and a hat-trick of indoor titles having won the recent tournaments in Basel and Paris.
Federer beat Tsonga in the opening round-robin match of the tournament and prevailed against the 26-year-old the week before in the Paris Masters final.
Tsonga, bidding to become the first Frenchman to win the season-ending championship since its inception in 1970, began in impressive fashion, though, and looked the more menacing player until Federer broke serve to love in the eighth game.
Federer grabbed an early break in the second set and looked poised for his 70th tour title when he served for the match at 5-4, only for Tsonga to produce some fireworks and level at 5-5.
An edgy Federer then squandered a 5-2 lead in the tiebreak and failed to convert his first match point at 6-5 when Tsonga belted a forehand down the line.
Tsonga then earned a set point and climbed all over a short Federer second serve to thrash another forehand deep into the corner which barely gave his opponent a chance to move.
Federer kept his nose in front in the deciding set despite some ferocious hitting from Tsonga and when the chance to seal the match presented itself again he made no mistake.