Tennis-Open-Ivanovic downs Venus to reach semis

Serbia's Ana Ivanovic (picture) kept her nerve under pressure to beat American Venus Williams 7-6 6-4 and reach the semi-finals of the Australian Open for the first time.

In an error-strewn encounter, the fourth seed came from 3-0 down in the second set to earn her first win in five meetings with eighth seed Williams, setting up a semi-final against Daniela Hantuchova of Slovakia.

"It's amazing, it was an amazing match and I'm just so thrilled to be through," Ivanovic said in a courtside interview.

"We had a lot of really long points and (Venus) is an amazing competitor. She was also playing really well I thought, as well.".

Neither player was at their best in a first set that saw six service breaks. Ivanovic led 4-2 at one stage as Williams, who wore heavy strapping on her left thigh, seemed to be struggling to get her usual power on serve.

The American hit back to force a tiebreak, though, only to lose it 7-3 as Ivanovic moved ahead.

Wimbledon champion Williams, runner-up here in 2003, hit back strongly at the start of the second as she took a 3-0 lead but Ivanovic won five of the next six games to serve for the match at 5-4.

After falling 15-40 down, she dug deep to save both break points and finally clinched victory when Williams sent a forehand wide.

Ivanovic said her improved fitness regime had helped her become a more consistent competitor.

"I always struggled with my fitness," she said. "In the last 18 months I have come so far, and become so much fitter, which also helps stop injuries. I am just so happy I could fight through.".

Ivanovic, who reached her first grand slam final at the French Open last year, said she expected a hard match against Hantuchova.

"She's definitely on a roll, she's playing some great tennis here. It's going to be a very hard match and it's a semi-final but it is a great chance for both of us.".