ANA Ivanovic is relishing the prospect of facing five-time champion Venus Williams in the fourth round at Wimbledon today – a repeat of their semi-final clash in 2007.

Williams won that match 6- 2 6-4 on her way to the title and, after beating sister Serena in last year’s final, the third seed is chasing a hattrick of victories at the All England Club.

But Ivanovic is in confident mood after improving round by round during the first week, saving a match point in her opening round but not dropping a set since and beating French Open semi-finalist Samantha Stosur in comprehensive fashion on Saturday.

Asked if she had kept anything in reserve to face Williams, Ivanovic said: ‘‘Definitely.

‘‘In the first three matches I was playing better and better and that’s what you want to feel going into the second week of a grand slam.

‘‘It’s been a while since I’ve gone far in a grand slam so I’m very excited to have the opportunity to do that here. I think my game suits grass very well. I still want to enjoy every match and see what happens.’’ Williams has won five of the six matches between the pair – Ivanovic’s only win coming in the quarter-finals of the Australian Open in 2008 – and the Serbian world number 12 is well aware of what to expect.

‘‘She likes to go for her first shot, she likes to dominate the points,’’ Ivanovic added.

‘‘I have to try to make a lot of returns, and obviously it’s going to be important for me to serve well because she has great first serves. If I can hold onto my serve and then put pressure on her, that would be key.’’ All eight fourth-round matches will be played today, with world number one Dinara Safina making her first appearance of the championships on Centre Court against former champion Amelie Mauresmo.

It is the first meeting on grass between the pair, and also the first in a grand slam since the 2006 US Open, when it was Mauresmo who topped the rankings.

The 29-year-old has not reached the quarter-finals of any grand slam since winning Wimbledon that year, while Safina has been runner- up in the first two grand slams of the year in Australia and France. An all-Russian and all-Elena clash takes place on Court Two, with fourth seed and Olympic champion Elena Dementieva up against compatriot Elena Vesnina, followed by Daniela Hantuchova taking on second seed Serena Williams.

Four teenagers have advanced to the last 16, with 18- year-old Caroline Wozniacki of Denmark takes on 19-yearold German Sabine Lisicki.

Lisicki took the biggest scalp so far, knocking out French Open champion and fifth seed Svetlana Kuznetsova.

But equally impressive was the performance of the youngest player left in the draw, 17-year-old qualifier Melanie Oudin beating sixth seed Jelena Jankovic in the third round.

Oudin takes on Agnieszka Radwanska, while Victoria Azarenka faces Nadia Petrova and Virginie Razzano and Francesca Schiavone clash on Court 18.