Victoria Azarenka collapsed and fell to the ground while chasing down a ball on the baseline and had to be taken off the court in a wheelchair Wednesday, withdrawing from the sweltering U.S. Open with what tournament officials said were "headache-like" symptoms.
The 10th-seeded Belarusian was trailing Gisela Dulko 5-1, 31 minutes into her match on another steamy day at Flushing Meadows, when she crumpled to the ground. She was taken to the hospital for tests.
The temperature had reached 90 degrees with 42 percent humidity by 11:30 a.m. and on-court temperatures topped 100 degrees. However, tournament officials released a statement saying heat did not appear to be the primary cause for the 21-year-old's withdrawal.
"Victoria Azarenka retired from her match with headache-like symptoms," the statement said. "She was taken to a nearby hospital for diagnostic testing. Out of respect to her privacy, we can not give any more details. However, we can say that this does not seem to be primarily a heat-related illness."
Wearing an all-black tennis dress, Azarenka had been moving slowly throughout the match. Before she served the first point in the seventh game, she hesitated and winced in pain. After the point, she kneeled down.
Two points later, while trying to run on the baseline, she stopped and crumpled to the ground, not appearing to twist or sprain anything. Medical personnel rushed out, draped a towel across her legs and yelled to the sideline to bring water. After a few minutes on the ground, being sheltered by an umbrella and with an ice pack on her neck, Azarenka was helped into the wheelchair and moved off the court. A trainer placed his hand on her neck to check her pulse.
"I was scared," said Dulko, who advanced to the third round. "She went to the floor. I was worried for her. I went to see her, brought some ice, did whatever I could do to help."
Dulko said the conditions were, indeed, brutal. For the second straight day, tournament officials put in place their extreme-weather policy, meaning women could ask for a 10-minute break if they split sets.
"It's tough to play out there," Dulko said. "It's really hot, really humid. You sweat so much, sometimes it's impossible to hold the racket."
In other early action Wednesday, former world No. 1 Ana Ivanovic defeated 21st-seeded Zheng Jie, 6-3, 6-0 in a match that took 56 minutes.
"Actually, yesterday I was feeling the heat the most," Ivanovic said. "I was practicing around 2 o'clock, and it was like, `OK, I think I'm done with half an hour."'
Other winners Wednesday afternoon included No. 20 Sam Querrey and No. 14. Nicolas Almagro. Ryan Harrison, an 18-year-old American qualifier, defeated No. 15 Ivan Ljubicic.
"The weather was my biggest enemy today," Ljubicic said. "I mean, throughout my career I struggled with the heat. I'm not really coping really well with that, and I tried all kind of different tactics to deal with it. I never find the right one."
Scheduled to play later Wednesday were defending champion Kim Clijsters, along with Andy Roddick, Andy Murray, Melanie Oudin and John Isner.
At the 2009 Australian Open, Azarenka won the first set of her fourth-round match against Serena Williams but quit during the second set while dizzy and in tears during a hot day in Melbourne.
Though the Aussie Open - played in midsummer in the Southern hemisphere - may be the most consistently hot Grand Slam tournament, they have roofs available on some of their courts. That makes the U.S. Open, where all matches are played outdoors, the toughest grind of the four major tournaments in many minds.
The year 2010 is going down as the hottest summer in recorded history in New York, which certainly is doing nothing to change that reputation.
The news of Azarenka's withdrawal traveled quickly through the tennis world.
"Did anyone watch Vikas match?? I really hope she is ok!" top-seeded Caroline Wozniacki said on her Twitter account, a few minutes after Azarenka fell. The previous night, Wozniacki defeated Chelsey Gullickson 6-1, 6-1 in a match that ended around 1 a.m.
Azarenka has won four career titles, most recently at Stanford last month, when she beat Maria Sharapova in the final. She reached the quarterfinals at the Australian Open this year, losing to Williams, the eventual champion.
Edmonton Oilers goalie Nikolai Khabibulin, a native of Russia, is a family friend and a mentor, taking her in with his family in Scottsdale, Ariz.