Top seed Wozniacki says self belief key to success

Poland's Caroline Wozniacki, who justified her top seeding at the US Open by defeating former champion Maria Sharapova, insists that she is a much improved player now and potent enough to beat top stars.

Wozniacki, surprise runner-up to Kim Clijsters at last year's Open, held her nerve against the power-hitting Russian to beat her 6-3, 6-4.

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"I got a lot of experience from last year and I'm just so happy that I won today and am through to the quarter-finals," The Telegraph quoted Wozniacki, as saying.

"I definitely think I've improved a lot, not only physically, but also I believe in myself more. I believe I can do it. Also I think I can mix up my game a little bit more than I could last year," she added.

Despite being benefited by Sharapova's 36 unforced errors, including nine double faults, Wozniacki said: "It was a really tough match, Maria is a great player so I knew it wasn't going to be easy."

Sharapova, meanwhile, was left lamenting the fact she had failed to seize break opportunities when she should have.

"I felt like I played a couple of good points and then made an easy error, hit a return long or missed a first serve. I didn't feel like I put much pressure on her," Sharapova said.

Wozniacki will now face Dominika Cibulkova in the quarter-final.