Russian Elena Dementieva accused Mary Pierce of using unfair tactics in their semi-final at the US Open [Images] on Friday, which the Frenchwoman won in three sets.

Pierce took back-to-back injury timeouts lasting 12 minutes after losing the first set and, as a rattled Dementieva lost her way, Pierce lifted her game to win 3-6, 6-2, 6-2.

"You can change the game by winning unbelievable points or by changing the rhythm, that's the fair point," Dementieva said.

"But by taking 12 minutes timeout, I don't think it was a fair play.

"Do I think she had something [injury], I don't think so. But she could do it by the rules and she did it.

"If that's the only way she can beat me, I mean that's up to her."

Pierce said she the injuries had been genuine.

"I would never do anything towards another player in that kind of a way," she said.

"I have too much respect for myself, for the game and for the person that I'm playing with, and for the fans and everything."

Dementieva had dominated the first set before Pierce called the trainer, and the Russian was forced to wait as the 12th seed had extended treatment, reportedly for injuries to her right thigh and to her back.

TAKE ADVANTAGE

When the match resumed, Pierce showed no signs of impaired movement, running down everything and lifting her game to become the first Frenchwoman to reach the US Open final.

Dementieva said she knew that Pierce would use everything she could to win the match.

"That's the way she wins," the Russian said. "That's the kind of player she is. She's trying to use everything, just to take advantage of some little distraction."

Dementieva said she would not use such tactics herself.

"I don't need it," she said.

"When I go on court, if I have something, I can tape it before the match.

"I really want to be just a better player, not to put any distraction or these kind of little things to distract the game of my opponent."

Pierce said the injuries had affected her early on.

"My back was bothering me from the very beginning of the match," she said.

"Maybe I was compensating already for my leg that I injured in the match against [Amelie] Mauresmo, so I really wasn't able to serve normally.

"After I lost the first set, I was like, 'OK, I need to get help,' because I can't play this way, I wasn't able to play my game. I wasn't into the match. I wasn't able to move."

Pierce denied the 12-minute break pushed the boundaries of gamesmanship.

"I'm 30-years-old, I've been on the tour 17 years. I don't believe in that," she said.

"I don't think that that will make a difference. I believe at this level, we're all very good players, we're all very mentally strong.

"I had injuries that I needed to attend to help me. I was hoping that would help, that I could play better, and it did. I just needed to do what I needed to do for my body and that was really it."

• Complete tennis coverage
• All you want to know about Sania Mirza