Britain's Andy Murray has ousted defending champion Roger Federer from the Masters Cup, rallying for a 4-6 7-6 (7-3) 7-5 victory.
Federer, a four-time winner of the season-ending tournament, appeared to be bothered in the third set by the sore back that forced him to withdraw during the Paris Masters two weeks ago. The Swiss star received treatment three times but refused to quit.
Federer saved seven match points while serving at 4-5, before Murray converted two games later, breaking when Federer sent a forehand long.
"A win over Roger Federer means almost as much as winning the Masters Cup to me," Murray said. "He's the best player of all time. He's still playing great.
"I know I'm going to be tired tomorrow, but this match meant a lot to me."
Murray, who had his left hand iced during one of Federer's time-outs, will play Russia's Nikolay Davydenko in the semi-finals. Federer's loss allowed France's Gilles Simon to advance. He will meet Serbia's Novak Djokovic.
The ninth game of the third set lasted 17 minutes and went to deuce 10 times. Federer fended off the last of the seven match points with an ace, then blasted another before Murray sent a forehand long.
"When you play against Roger, you got to expect him to play some great stuff, especially when he's behind," Murray said. "He hit a couple of aces, a couple of big forehands. I missed a couple of returns I maybe shouldn't have."
Federer tried to force a tiebreaker, but with the match clock reaching three hours, he committed three forehand errors while serving at 15-15.
Murray, who came in as one of the few players with a winning record against Federer at 3-2, already had clinched a semi-final spot from the Red Group. But he lived up to his promise not to take it easy, wanting to avoid the prospect of facing Federer again if both were to make the final.
Federer was trying to repeat last year's feat of coming back after losing his opening-round match.
The atmosphere was more akin to a final than the last match of group play. Qi Zhong stadium was packed, and while the crowd overwhelmingly favoured Federer, Murray has won over a lot of fans in his debut here.
They all got their money's worth, with plenty of drama and great tennis.
Gilles Simon earlier beat Radek Stepanek 6-1 6-4 in what was essentially a meaningless match because Federer controlled his own destiny - win and he was through, lose and go home.
"It was easier tonight because my match was not really important," said the ninth-ranked Simon, who got in when a sore knee forced top-ranked Rafael Nadal to pull out of the season-ending tournament before it began.
The 26th-ranked Stepanek - added to the eight-man draw when Andy Roddick pulled out on Wednesday with a sprained ankle - already had been eliminated.
AP