MELBOURNE, Australia -- Down four match points and hobbling on her injured left ankle, defending champion Kim Clijsters somehow rallied for a dramatic 4-6, 7-6 (6), 6-4 win over Li Na at the Australian Open on Sunday.
Clijsters was in pain from the ankle she twisted in the seventh game. Li was just a bundle of nerves. The French Open champion failed to serve out the fourth-round match at 5-4 in the second set, but then led 6-2 in the tiebreaker. Again Clijsters refused to yield.
"I said in my mind, keep fighting," Clijsters said. "You never know what happens on the other side of the court."
Wozniacki advanced with a chance of keeping her top ranking by beating former No.1-ranked Jankovic.
"My confidence is high, my fitness is good, my play is improving and I'm very positive," said Wozniacki, who is looking for her first Grand Slam title.
Li's best chance to win -- and gain revenge for her three-set loss to Clijsters in last year's final -- came on her fourth match point.
Clijsters played a poor drop shot, giving her opponent the chance to put the ball into the open court. Instead, Li tentatively hit the ball almost straight back to Clijsters, who sent up a perfect lob that dropped just inside the baseline.
"Of course I was nervous," Li said. "If you're nervous, you could not think too much, right?"
Clijsters won six straight points to take the tiebreaker and the first four games of the deciding set.
"I'm not saying that that forehand drop shot was a good choice, but you make decisions. Luckily, that one turned out OK," Clijsters said. "I think she was a little bit lost or maybe a little bit confused at that time."
Clijsters then overcame a wobble of her own, losing her serve at 5-2 in the third set, before finally closing out the fourth-round match on her second match point.
Li broke down in tears at the end of her post-match news conference.
"Maybe 6-2 up in the tiebreak I was a little bit shocking," she said.
Clijsters was hurt in the first set while serving at 3-all and 30-all. As she hit a forehand, her left foot got stuck on the surface and the ankle twisted awkwardly.
She got up to finish the point but then immediately called for the trainer and had the injury strapped.
Clijsters' movement was clearly slowed when she resumed but, playing in her last Australian Open before quitting tennis at the end of the season, she said she didn't want to bow out in Melbourne with a retirement.
"I knew if I could just try to let the medication sink in or if I could get through the first 20 minutes, half hour, I think the pain would go away a little bit and then maybe with the adrenaline I could just fly through it," she said.
The injury seemed to affect Li just as much. The 29-year-old, who won last year's French Open to become the first player from China to win a Grand Slam singles title, looked increasingly stressed as the match progressed.
After 2 hours, 23 minutes, she netted a backhand to put Clijsters through to the quarterfinals. The Belgian said she was hopeful her ankle would hold up after ice treatment.
Victoria Azarenka was the first player to reach the quarterfinals when she beat Iveta Benesova 6-2, 6-2. The third-seeded Belarusian is yet to drop a set at the tournament and will next meet eighth-seeded Agnieszka Radwanska.
"I would be a liar if I said I didn't care about it," Azarenka said.
Information from The Associated Press was used in this report.