Ivanovic vows to regain form after exit

Former world number one Ana Ivanovic is determined to get back to her best after winning just three games in her fourth-round clash with defending champion Kim Clijsters at the US Open.

Clijsters won 6-2 6-1 on Sunday to extend her winning streak at Flushing Meadows to 18 matches, the 27-year-old having won the title in 2005 and then coming out of retirement last year to lift the trophy again in only her 14th match and third tournament since returning to action.

Ivanovic became world number one when she won the French Open in 2008, but is currently ranked 40th after a number of injury problems and a loss of form.

The 22-year-old was forced to retire from her previous match with Clijsters in the semi-finals in Cincinnati recently with a foot injury, and was not too downhearted despite yesterday's display.

Asked if the experience had given her the desire to get back to where she once was, Ivanovic added: "It does, it definitely does.

"You practise and work hard for these kind of matches, to be in a position to play against top players in a big stadium and a big moment.

"That was in some ways a nice feeling. That's what I want to work hard towards achieving, playing more of these matches and putting myself in a position to do so.

"Besides this match against Kim, I think I played really well. I was feeling really good in the court and just swinging through, hitting my favourite shots again. Today I was just a little bit slow. I think nerves crept in.

"I was on the big stage again, I hadn't had that feeling for a long time. Lots of emotions came back and I felt just a little slow and out of it. I had my opportunities in the beginning that I didn't convert, so that was a little bit disappointing, but she played well."

Clijsters said: "I've always played really good matches in America, I enjoy playing on hard courts and you automatically do well in places where you feel good and have done well before, so the US Open is a special tournament for me."

The Belgian will now face Australia's Samantha Stosur, who won an epic match against Russia's Elena Dementieva 6-3 2-6 7-6 (7/2) in the evening match which finished just after 1.30am local time. Fifth seed Stosur survived four match points to book her first appearance in the last eight at the US Open.

The other quarter-final in the bottom half of the draw will see French Open champion Francesca Schiavone take on third seed Venus Williams.

Sixth seed Schiavone beat Anastasia Pavlyuchenkova 6-3 6-0, while Williams had to battle hard to see off Shahar Peer 7-6 (7/3) 6-3.

After a first week characterised by far too many one-sided "contests" in the women's singles, Williams was pleased to have come through a genuine match.

"It's always good to have a tough match, a match where you have to challenge yourself against your opponent and the conditions and everything and just continue to stay tough and to stay positive," the two-time US Open champion said.

"We always have had very competitive matches, so I know it's not gonna be something I just walk through when I play against her. I have to stay focused and ready to take every point or else she will. It was a good challenge."