Paris: Russian superstar Maria Sharapova pulled out of the WTA Paris Open tournament due to illness as Kim Clijsters eyed a return to the top of the world rankings.
Sharapova, the world number 13, has been suffering from a throat infection since the weekend and consulted a doctor on Thursday morning before deciding to pull out, having been granted a place in the draw as a wild card.
"I`ve really done everything to be ready, but unfortunately, I`m unable to play," Sharapova said in a statement.
"I want to apologise to my fans and to thank the tournament for having been so understanding and supporting me."
Sharapova was replaced by `lucky loser` Stephanie Cohen-Aloro of France who went on to lose 7-5, 6-3 to America`s Bethanie Mattek-Sands in the second round.
Australian Open champion Clijsters will replace Denmark`s Caroline Wozniacki if she wins her quarter-final tie on Friday.
The Belgian, who was top for 12 weeks in 2003 and seven in 2006 before her retirement and subsequent return to the game two years later, will tackle Jelena Dokic of Australia for a place in the last four.
Dokic, a qualifier, fired 10 aces in her 6-4, 7-6 (7/4) win over Russian fifth seed Nadia Petrova.
"I was confident and put pressure on her," said Dokic. "I played great in the first set, went down a little in the second but I managed to pull through.”
"I have already played five matches here, things are getting better and better.”
"I have nothing to lose against Kim in the next match. She`s almost number one again. I will just go out and enjoy it."
Clijsters and Dokic won the French Open junior doubles title as a team in 1998, and even won a WTA doubles title together, at Los Angeles in 2002.
They have also clashed nine times, with Dokic winning three of those matches - including their last meeting, when Clijsters was ranked No.1, at Zurich in 2003.
Clijsters leads the overall head-to-head series with Dokic, 6-3.
Dokic was delighted to see off Petrova in a match where she did not drop serve.
"Nadia and I know each other very well. We played doubles as juniors," Dokic said. "It was great to follow up on my win against Lucie Safarova. Two good wins in a main draw is great.
"I`m playing well, moving well and serving well, and I`m mentally strong. At the moment I think I can stay with these girls. I did a lot of hard work at the end of last year. I`m looking to play a lot of tournaments and have a good year."