Novak Djokovic ended Roger Federer's reign as the king of the O2 Arena in a brilliant final at the Barclays ATP World Tour Finals in London.
Federer had won the last two titles and was looking to extend his record to seven in the tournament as a whole but he could not capitalise on good starts in both sets and went down 7-6 (8/6) 7-5.
Djokovic, who saved two set points in the second set, it was the perfect way to end another stellar season and as undefeated champion he goes home with $1,760,000 in prize money.
It was only the fourth time the top two players in the world have played in the final since the inaugural tournament in 1970.
Federer and Djokovic had met 28 times previously, with the Swiss leading 16-12, while he had also won their two most recent matches, at Wimbledon and in Cincinnati in August.
In contrast, this was Djokovic's first final in London, although he did win the title the final year the tournament was held in Shanghai in 2008.
Yesterday Federer had begun sloppily against Andy Murray before recovering to win in three sets, but today he was sharp from the start, winning his opening service game in less than a minute.
The same could not be said for Djokovic, who started his first service game with a double fault and could not recover.
Remarkably Federer won the first nine points but Djokovic is the master of digging in and he steadied the ship before breaking back for 3-2 when his opponent's level finally dropped a little bit.
Yesterday it had been notable that Federer had the majority of the crowd support despite facing a British player but today it appeared more even, with Serbian flags punctuating the ubiquitous Swiss cross.
And Djokovic was firmly back in the match now and pushing for another break, which he achieved after a long ninth game.
That left the 25-year-old serving for the set, and he had a set point but he could not take it and there was a huge cheer as Federer broke back when Djokovic netted a forehand.
The Serb was on the floor in the next game as he flung himself after a Federer forehand, which necessitated a patch-up from the trainer, but he recovered from 0-30 to force a tie-break.
Like the rest of the set, it was nip and tuck. Djokovic had the first set point but Federer saved it in a remarkable rally and let out a roar.
A cry of 'Roger, Roger' rang out but Federer followed up with an errant backhand and this time Djokovic capitalised.
Djokovic was soon on the back foot again, though, as Federer piled on the pressure at the start of the second set, and he got his break at the fourth time of asking.
Federer was up against it having never won on the eight previous occasions he had dropped the first set to Djokovic, while it was the first time he had lost the opener in his eight finals at the tournament.
The world number two kept pressing and missed a chance for a double break in the fifth game, which he was almost made to regret as Djokovic, the man who simply will not go away, pushed for a break of his own to level at 4-4.
Federer held on and brought up two set points at 5-4 but he let the chance slip away and this time Djokovic did capitalise, a forehand into the corner too much for the champion.
That drew a full-blooded roar from the Serb, and now the pressure was on Federer to stay in the match. He could not do it, Djokovic driving a backhand passing shot beyond the despairing reach of his opponent on his first match point.