Dementieva injured in Florida

Dementieva suffered a foot injury during her win

Third seed Elena Dementieva was forced to withdraw after progressing into the last eight at the Bausch & Lomb Championships.

Dementieva struggled with a foot injury during a 6-4 6-3 win over fellow Russian Elena Likhovtseva, which saw her join top seed Martina Hingis in the next round.

She hurt her left heel while running down a drop shot, and was seen walking with the aid of crutches after her win and was later forced to pull out of the tournament.

"I hurt my heel on the last point of the first set, and as the match went on I tried to forget about it," said Dementieva.

Hingis crushed 15th seed Nagyova

"But I need to have it looked at further now to see what is wrong."

Elsewhere, Hingis made short work of her opponent Henrieta Nagyova.

On a hot, humid day, the Swiss star eased into the quarters with a swift 6-1 6-3 dismissal of the 15th seed.

Hingis will next face seventh-seeded veteran Arantxa Sanchez-Vicario, who won her 28th career title at the Porto tournament last week.

Sanchez-Vicario has beaten the world number one just once in 16 career meetings - on clay at Hilton Head in 1996.

"I feel I have a very good record against her and we know each other's games inside and out," Hingis said.

I'm very satisfied because I always felt in control of the match

  Martina Hingis

"But I was always able to come out the luckier one."

Hingis, looking for her fourth title of the year, felt she had only one brief lapse against the 31st-ranked Nagyova.

This was when she allowed the Slovakian to level the second set at 2-2 after taking a 2-0 lead.

"I played a very good first set and was focused, but I let her back in the game in the second set," she said.

"I'm very satisfied because I always felt in control of the match."