Roddick Out Of US Open

Andy Roddick gave Novak Djokovic a run for his money, but the former champion faltered late in a prickly quarter-final slugfest at the U.S. Open on Thursday.

Djokovic, the tournament's third seed, prevailed 6-2, 6-3, 3-6, 7-6 to advance to the semifinals at Arthur Ashe Stadium in Flushing Meadows, N.Y.

The second-seeded former world No. 1 Federer held off qualifier Gilles Muller of Luxembourg 7-6 (7-5), 6-4, 7-6 (7-5) on Day 11 on the hardcourts at the USTA Billie Jean King National Tennis Center.

Federer was this year's Wimbledon and French Open runner-up to Spanish stalwart Rafael Nadal, who supplanted the Swiss atop the men's rankings last month.

Djokovic topped Federer in the semifinals of the Australian Open earlier this year before taking Jo-Wilfried Tsonga for his first career Grand Slam title.

Saturday's other semi will pit the five-time major champion Nadal against sixth-seeded Brit Andy Murray, as those two men won their quarterfinal matches here on Wednesday. The 21-year-old Murray will appear in his first-ever Grand Slam semi.