Murray, Nadal complete US Open semifinals line-up

Defending champion Rafael Nadal and world number four Andy Murray guaranteed a US Open Super Saturday line-up, completing an all-star, top-four lockout of the semi-final places.Second seed Nadal cruised past 2003 champion Andy Roddick, the American 21st seed, 6-2, 6-1, 6-3 and will tackle Murray for a place in Mondays final.Murray, the fourth seed, became just the seventh man to feature in all four Grand Slam semi-finals in the same year when he thwarted big-serving American John Isner, the 28th seed, 7-5, 6-4, 3-6, 7-6 (7/2).Top seed Novak Djokovic, who will also be playing in his fourth Grand Slam semi-final of 2011, will face five-time champion Roger Federer, the third seed, in Saturdays other semi-final.Nadal pulled off his seventh win in 10 meetings against Roddick and was untroubled as the 29-year-old American was slowed by a left thigh injury which twice needed treatment and the all-court dominance of the Spaniard.Nadal, who became the youngest man to complete a career Grand Slam when he won here last year, will be playing in his fourth successive US Open semi-final and will be buoyed by having defeated Murray in the semi-finals at the French Open and Wimbledon.Murray, who is vying to become the first British man since 1936 to win a Grand Slam title, said he thinks he can contend on the Flushing Meadows hardcourts despite trailing Nadal 12-4 in career meetings.Djokovic, who has already won the Australian Open and Wimbledon titles this year, made sure of his semi-final place on Thursday when Serbian teammate Janko Tipsarevic quit with an injury with the top seed 7-6 (7/2), 6-7 (3/7), 6-0, 3-0 to the good.Federer eased past Jo-Wilfried Tsonga 6-4, 6-3, 6-3 to gain revenge for his shock Wimbledon quarter-final defeat to the Frenchman.The 30-year-old Federer, who holds a record 16 Grand Slam titles, has every right to be confident going into Saturdays showdown.His French Open semi-final victory over Djokovic in June brought an end to the Serbs stunning 43-match winning run, a streak which stretched back to December 2010 when he led his country to a maiden Davis Cup.