DUBAI, United Arab Emirates (AP) -- Anna Chakvetadze collapsed on the court at the Dubai Championships on Wednesday and had to retire from her match against top-seeded Caroline Wozniacki.
The 23-year-old Russian was serving for the second set at 5-3. After a long rally that Wozniacki won, Chakvetadze wobbled before fainting.
She was given extensive medical treatment during a 7-minute delay and returned for one more point before forfeiting the match and tearfully hugging Wozniacki.
Organizers said Chakvetadze, who lost the first set 6-1, had a stomach illness.
Wozniacki said it was a "shock" to see someone she considers a good friend collapse so suddenly. When she approached her, Chakvetadze said she had felt dizzy.
"Suddenly, I just see her collapse on the court. I didn't know what happened," the 20-year-old Wozniacki said. "It was a shock. It was scary. To see someone collapse on other side, it's not a nice sight. I just want to make sure she was OK."
Wozniacki, who needs to reach the semifinals in Dubai to retake the No. 1 spot she lost on Monday to Kim Clijsters, looked as if she was coasting to an easy victory after winning the first set in 22 minutes.
But then Chakvetadze rallied in the second and seemed on the verge of tying the match - which clearly rattled the normally calm Wozniacki.
At one point, Wozniacki tossed her racket in frustration.
"In the first set, I didn't get into the game that much," Wozniacki said. "She was making a lot of mistakes. Suddenly, she started to go for it. I just need some time. I started playing better at the end of the second set."
In the first big upset of the tournament so far, Australian Open finalist Li Na wasted four match points in a 6-7 (6), 7-6 (6), 6-2 loss to Belgian Yanina Wickmayer.
The fifth-seeded Li led 6-2 in the second set tiebreaker before Wickmayer reeled off the next six points to even the match. The 25th-ranked Belgian broke for a 4-2 lead in the deciding set when Li double faulted.
Li then hit a forehand long to make it 5-2 on the way to the Belgian's victory - her second in two meeting against the No. 7-ranked Chinese player.
Wickmayer plays Israel's Shahar Peer on Thursday in the third round.
"It's always tough to start a set when you know you had four match points, so I knew I had to start really aggressive in the third set and try to put a lot of pressure on her," Wickmayer said. "I know I been there before. Also had match point in the second set and didn't make it. Every bad error that you make or every point that's not going the way want to it to, you keep thinking back on those four match points."
Li's loss is her latest disappointment in Dubai, where she has failed to go beyond the quarterfinals in six appearances. She refused to talk to reporters after her match.
In the afternoon matches, Grand Slam winners Francesca Schiavone and Svetlana Kuznetsova both won to set up their first matchup since their nearly five-hour epic at the Australian Open.
Schiavone topped Chinese qualifier Zhang Shuai 6-3, 6-1 while Kuznetsova, a two-time runner-up in Dubai, took the long road to beat Tsevetana Pironkova of Bulgaria 5-7, 6-2, 6-4 for a third straight time.
The wins put them on course to meet on Thursday, more than three weeks since their fourth-round encounter in Melbourne went 4 hours, 44 minutes in the longest women's Grand Slam singles in the Open era. Schiavone won.
Looking forward to the match, Schiavone smiled and said, "After two hours, I'll take the racket and put it in the bag.
"I really want to play against her because we know each other, we play good tennis and we can enjoy it and improve."
Kuznetsova leads their matchups 8-5 since 2003, but Schiavone has won the past two.
Second-seeded Vera Zvonareva beat Roberta Vinci of Italy 6-3, 6-1. The Russian, still seeking her first title in more than a year, has exited in the Dubai quarterfinals in the past two years.
"It's never easy to play Roberta, she's a tricky player," Zvonareva said.
Fourth-seeded Sam Stosur handled Pattaya Open runner-up Sara Errani of Italy 6-0, 6-1 in 55 minutes, and seventh-seeded Victoria Azarenka of Belarus overcame seven double faults to beat Chinese qualifier Peng Shuai 4-6, 6-2, 7-6 (5).
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