Roger Federer claimed a record sixth victory in year-ending ATP championships after defeating Jo-Wilfried Tsonga 6-3 6-7 6-3 at the World Tour Finals.
The 16-time grand slam champion, who was also playing in his 100th career final, held his nerve to fight off a spectacular comeback from his French opponent.
Tsonga looked to be heading for a quick defeat as Federer served for the match in the second set, but some free-hitting sparked him into life and he levelled the match in a tie-break.
But Federer hit his stride again in the third and the sixth seed finally buckled under the pressure, allowing the defending champion to complete the win and surpass Pete Sampras and Ivan Lendl on the list of multiple Tour Finals winners.
Federer became the tournament's oldest winner with his 70th final victory and will take a winning streak of 17 matches into next season, said: "I couldn't be more happy and I couldn't be more exhausted."
The Frenchman had simply overpowered the 16-time grand slam champion in becoming the first player to beat him at a grand slam from two sets down at Wimbledon, and the same thing looked possible here as he piled the pressure on in the early stages.
But crucially the break did not come and in the eighth game Federer made his move, winding up his backhand to earn three break points and taking the second when his opponent netted an attempted drop volley.
That left the fourth seed serving for the set and, although Tsonga saved two set points in impressive fashion, there was nothing he could do on the third.
The frustrated Frenchman then had to dig himself out of a hole when he began the third game of the second with two double faults, but dig he did, two aces on break points neatly rescuing the situation.
The tables had well and truly turned, though, and Federer did clinch the break two games later with a thumping forehand return.
Tsonga was hanging on by his fingernails but he was determined not to make it easy and he fought off another break point in the seventh game with a brave drop shot.
And that became very significant as Tsonga made a last-ditch attempt with Federer serving for the match, using his power brilliantly to bring up his first three break points and taking the third.
The crowd acclaimed their new hero, who continued to live dangerously on his serve but hung on as into the tie-break they went.
Having worked so hard to earn his chance, Tsonga gave away a cheap couple of points and at 5-2 he was staring down the barrel once more.
Again he clawed back to level before an ace earned Federer his first match point, but Tsonga powered away a forehand winner.
Another service winner gave him a set point and he took it with a stunning forehand return.
It was no more than the world number six deserved and Federer, who has made a bit of habit this season of snatching defeat from the jaws of victory, had to refocus quickly.
He did not panic, though, and in the eighth game of the decider his chance arrived. Twice Tsonga saved break points but a third arrived and this time he dumped a forehand wide.
And there were to be no more heroics, Federer sealing victory with an easy forehand volley to add to the titles he won in 2003, 2004, 2006, 2007 and 2010, with his only defeat in a final coming against David Nalbandian in 2005.