Murray knocks Federer out of Masters Cup

Britain'sAndy Murray sent defending champion Roger Federer crashing out of the Masters 

Murray came from a set down to win 4-6, 7-6 (7/3), 7-5 after Federer, apparently hampered by a back injury, saved seven match points in a gripping final set.

The result boosts Murray's chances of winning the eight-man season finale on debut and means France's Gilles Simon also reaches the last four.

"I would have liked to have won on the first match point but I played a couple of bad shots and he hit some aces and some big forehands," Murray said.

"I just had to find a way to come back after that. He was a little bit tired at the end and physically struggling and I had that at the back of my mind."

Federer had never failed to reach the Masters Cup semi-finals in seven straight appearances, winning four titles including the last two.

The 13-time Grand Slam champion, who was forced out of the Paris Masters with a back strain, needed to beat Murray to stay in the tournament after losing to Simon earlier.

Federer was also weakened by a stomach bug in Shanghai, but he started in imperious form and snapped up the first break point of the match at 2-1.