NEW YORK, (Reuters) – Victoria Azarenka’s on-court  collapse in the scorching heat at the U.S. Open was a result of  hitting her head in the gym ahead of the match, the 10th seeded Belarussian said yesterday.

Azarenka slumped to the ground while trailing Argentina’s  Gisela Dulko 5-1 on the Grandstand court and was taken off  court in a wheelchair and treated in hospital where she was  diagnosed with a mild concussion.

“I was warming up in the gym prior to my match against  Gisela Dulko when I fell while running a sprint. I fell forward  and hit my arm and head,” Azarenka said in a statement.

“I was checked by the medical team before I went on court  and they were courtside for monitoring. I felt worse as the  match went on, having a headache and feeling dizzy. I also  started having trouble seeing and felt weak before I fell.”
The 21-year-old Belarussian, wearing a black dress in  temperatures nearing 90 Fahrenheit (32 Celsius), showed few  signs of any medical problem as she came on court to warm-up.

But she lost her opening two service games and called the  trainer as early as the third game. She received treatment to  her injured arm and also complained of blurred vision.

It became increasingly clear that she was in difficulty as  she took time out between every subsequent point and was ill at  ease on her feet.
Then, while serving for the fourth time in the match, she  collapsed on the baseline, leading to gasps from the crowd and  a rush of medical staff onto the court who placed a white towel  over her legs.

“I was scared,” Dulko told reporters after witnessing her  opponent receiving treatment on the court before being taken  away in a wheelchair as a medical official checked her pulse.

“She went to the floor – I was worried for her. I went to  see her, brought her some ice, did whatever I could to help.”

This is Azarenka’s second retirement from a grand slam  event. Having taken a set off Serena Williams at last year’s  Australian Open, she pulled out citing dizziness and illness.  Dulko now faces 20th seed Anastasia Pavlyuchenkova in the  third round.