Li, seeded sixth, lost 6-2, 7-5 to Romania's Halep, suffering first-round exit for the second time in a row.

　　Li admitted she was losing confidence from her under-par performance since the French Open.

　　"For me, I really want to do well after Roland Garros. But it's not easy to do. Always easy to say, but always lose early. Now I even lose all the confidence on the court," said Li, who since Roland Garros had not won consecutive matches until last week when she reached the semifinals at New Haven.

　　"Before the match, I talked to my coach. I say, I didn't have good timing to hit the ball. He tell me everything is perfect, everything is fantastic.

　　"I say, yes, everything is fantastic, but I always lose first round. I mean, this is not fantastic. I think we need to change something. I think maybe the team or coach just try to give me confidence, but I don't think I get."

　　The second round at Flushing Meadows will be without all three of this year's major champions. Australian Open winner Kim Clijsters withdrew because of injury, while Wimbledon champ Petra Kvitova lost on Monday.

　　It's the first time that's happened since 1971.

　　The 19-year-old Halep beat a top-10 player for the first time in four tries. The Romanian was playing in her second U.S. Open match.