Home favorite Melanie Oudin was stopped Wednesday when the unseeded teenager lost 6-2, 6-2 to put her dazzling U.S. Open run in an end.
With a hail of unforced errors, Oudin lost to steady Dane Caroline Wozniacki, seeded ninth, in the women's singles quarterfinals of this year's final grand slam.
"I've had a great run this tournament," said the 17-year-old Oudin. "I'm a perfectionist, so... losing isn't good enough for me. Today I was a little bit fragile."
Wozniacki next meets Belgium's unseeded Yanina Wickmayer.
China's Zheng Jie and Yan Zi lost to fourth seeds Serena and Venus Williams 7-5, 6-4 in the women's doubles quarterfinals, wrapping up the campaign of all four Chinese players here.
However, it has been the best ever results for China in the hard court event with Zheng/Yan reaching the women's doubles last eight and Li Na making the women's singles quarterfinals.
On the men's part, top seed Federer was challenged Wednesday but managed to beat 25-year-old Robin Soderling of Sweden 6-0, 6-3,6-7, 7-6.
Federer won the final set tiebreaker 8-6 and marched into his 22nd consecutive grand slam semifinals.
In the semifinals, the five times defending champion will face fourth seed Novak Djokovic.
(Xinhua News Agency September 11, 2009)
