Andy Murray's season ended in defeat by Roger Federer in the semi-finals of the Barclays ATP World Tour Finals in London.
The US Open champion made a great start at the O2 Arena but Federer clawed his way back into the match and, after taking the first set on a tie-break, raced away with the second to win 7-6 (7/5) 6-2.
Federer now goes through to Monday night's final against world number one Novak Djokovic, who beat Juan Martin Del Potro earlier on Sunday, where he will bid for a third successive title at the end-of-the-season tournament.
The atmosphere was electric throughout, and Federer said: "It was a special match. You can't tire of nights like this. That is why I keep practising in front of no people, it inspires you to keep working hard."
This was the third big meeting of the year for the pair in London after the finals of Wimbledon and the Olympics, where Murray turned his Centre Court tears into gold. Their last match came in Shanghai last month, Murray again the victor, and he was looking to make it six successive sets won against the world number two.
Federer lost for the first time in three years here against Juan Martin Del Potro on Saturday and made a poor start on Sunday night as he lost his opening service game. But he retrieved the break in the eighth game as Murray netted a forehand.
Suddenly it was the Scot under pressure serving to stay in the set but he held firm to set up a tie-break. Murray had the early advantage but again Federer hit back and created two set points by winning a stunning rally, prompting his opponent to smack his racquet on the court. Murray saved one but not a second.
Murray had come back to beat Federer from a set down four times before but not for almost four years, and he was in even deeper trouble when, from 40-0 up, he was broken to trail 2-1 in the second set.
The 25-year-old looked a little disconsolate, and he was failing to make an impression on the Federer serve as the second seed closed in on place in the final. It was all but game over for Murray when the champion broke once more with a searing cross-court backhand to make it 5-2 and leave himself serving for the match.
And that proved to be no problem, Federer sealing victory with a forehand down the line and leaping into the air in delight.