SHANGHAI (AFP) - Britain's Andy Murray hailed the pulsating Masters Cup win over defending champion Roger Federer as one of his best this season. The 21-year-old Scot downed the injured ex-number one 4-6, 7-6 (7/3), 7-5 to reach the year-end tournament's semi-finals on his debut and remain in line for a 1.34 million dollar payday. Murray, who was on court for more than three hours until after 11:00 pm, has less than 24 hours to recover before his last-four clash with Russia's Nikolay Davydenko. "I won't know how much it's taken out of me till tomorrow. But it was a great match," he said. "You know, so many twists and turns. The first set was relatively straightforward for him. But the second and third set, you never knew what was gonna happen. "Then that tie-break in the second set had some amazing points. I had that feeling that it was going to be one of those matches where it's gonna go right to the wire. I was glad I pulled it out." Federer, who was hampered by a back injury and a stomach bug, saved seven match points in a gripping final set. Murray improved his record to 4-2 against the Swiss including three wins this year. The Scot said the match ranked alongside his rain-affected Wimbledon quarter-final defeat to eventual champion Rafael Nadal. "With this sort of drama, the ups and downs, it's probably alongside my match with Nadal, where I had to deal with the sort of rain delay and stuff," he said. "This one, obviously with him having a slight injury, I heard he was sick, and also having all the match points and all the chances that I did have, that made it even better for me." Murray now appears favourite for the title after continuing his strong form of recent months in reaching the US Open final and claiming back-to-back Masters series titles. World number three Novak Djokovic plays France's Gilles Simon in Saturday's other semi-final.