Roger Federer withstood an early barrage to see off Andy Murray in straight sets and reach the final of the ATP World Tour Finals in London.
The Swiss will try for a seventh season-ending title on Monday after ending the best season of Murray's career with a 7-6 (7-5) 6-2 win.
Federer will play world number one Novak Djokovic in the final.
Murray heads into the off-season at the end of a memorable a year that saw him win the US Open and Olympic gold.
"I think he played well," said Murray of the opponent who recovered from one set adrift to beat him in this year's Wimbledon final.
"I didn't think it was an incredibly high standard in terms of length of points - there were a lot of quick points.
"Once he gets ahead, he's incredibly hard to stop. He tends to play better and better when he gets up. I feel like I gave him that advantage at the beginning of the second set."
And reflecting on his season, Murray added: "It's been an incredibly positive year. I would have love to have finished the year on a win, of course, but that didn't happen. But for me it's been the best year of my career by a mile."
It had looked as though the British number one might be able to deliver his home crowd another glorious sporting moment to finish off an extraordinary 2012.
He began in aggressive fashion, while Federer was spraying his usually devastating forehand all round the O2 Arena, with an error on that side handing Murray an immediate break.
It only served to heighten a feverish atmosphere as Federer's huge army of fans more than held their own among the 17,800 spectators.
Asked afterwards about the level of backing for his opponent, Murray said: "Whenever you play Roger anywhere in the world he gets great support and he deserves that because of everything that he's achieved."
Murray was racing away with the set and Federer did well to claw his way back from 0-30 at 3-1 down, and that escape appeared to shift the momentum.
It needed several heavy serves around the 135mph mark to keep Murray ahead in game six, but with his forehand now finding their targets Federer got back on level terms at 4-4.
The 31-year-old Swiss was now in charge, pushing for another break before recovering a 3-1 deficit in a tense tie-break.
Another superb forehand got him back to 3-3 and the pressure began to tell on Murray, who swiped his racquet in anger after an error handed Federer two set points.
Murray's excellent start was long forgotten now and the Scot crept past Federer's 14 unforced errors by giving up a 15th on set point.
After a 62-minute opening set, the second flashed by in 33 minutes as Federer got into full flow.
Murray helped him out by giving up a 40-0 lead in the third game, with four errors largely the result of his rampant opponent, and another break soon followed.
Always a great front-runner, the 17-time Grand Slam champion swarmed all over the net and kept Murray pinned back as he extended his incredible run in the season finale.
"It was the third time in London this year for the two of us and the crowd was electric," Federer said in the wake of his win.
"I have been around the block a few times and that was something. 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."