New York:Roger Federer had a tougher fight than might have been expected at the US Open on Wednesday before progressing to his 22nd straight Grand Slam semifinal.
The top-ranked Swiss came out with a 6-0, 6-3, 6-7 (6), 7-6 (6) victory over No.12 Robin Soderling of Sweden that extended his streak to 39 straight wins at the US Open.
"Not what I aimed for, that's for sure," Federer said of his semifinal streak. "It's probably one of the greatest records for me personally in my career.
"It's a great relief to come through, because Robin started playing better and better as the match went on," Federer said. "I knew he'd be tough, but the beginning was way too easy. He found his way into the match."
Federer will play No. 4 Novak Djokovic in the semifinals, after the Serb's 7-6 (2), 1-6, 7-5, 6-2 win over Spaniard Fernando Verdasco.
Djokovic moved into the last four at the U.S. Open for the third straight year. In 2007 he reached the final but lost to Federer, then last year he was beaten by the same man in the semifinals. Now he gets another chance to finally beat his Flushing Meadows nemesis.
In Thursday's second set of men's quarterfinals, No. 3 Rafael Nadal will play No. 11 Fernando Gonzalez of Chile and No. 6 Juan Martin del Potro of Argentina will take on No. 16 Marin Cilic of Croatia.
In the women's quarterfinals on Wednesday, the impressive run of 17-year-old American Melanie Oudin came to an end at the hands of Caroline Wozniacki, with the No.9 seed becoming the first Danish woman to reach a Grand Slam semifinal.
Against Wozniacki - a 19-year-old who has won more matches than anyone on the tour this year - Oudin faced a carbon copy of herself, harrying to get every ball back into play.
While Oudin was able to fight back from deficits to beat the likes of Elena Dementieva and Maria Sharapova in earlier rounds, Wozniacki was a tougher nut to crack.
"She plays incredible defense," Oudin said. "Makes me hit a thousand balls and really is a really great player. I mean, I don't know what else I could have done."
Wozniacki will face 50th-ranked Yanina Wickmayer in an unexpected semifinal, with the winner going up against either Serena Williams or Kim Clijsters in the final.
Wickmayer lost her mother to cancer at age 9 and took up tennis to clear her head in the aftermath. She and her father moved from Belgium to enrol at an American tennis academy, and 10 years later she is into the final four at Flushing Meadows.
"He just gave everything up for me," Wickmayer said. "He just left. He listened to a girl that was 9 years old and left his life, left his dreams. I'm always going to respect him for that."