Third seed Amelie Mauresmo said she had mixed feelings after reaching the fourth round of the Australian Open when her opponent Michaella Krajicek retired from their match suffering from heat stress on Saturday.

Mauresmo had raced through the first set of their third-round match on Rod Laver Arena 6-2 when Krajicek called for assistance as temperatures hit 38 degrees celsius (100.40F).

While concerned for her teenage opponent's well-being, the Frenchwoman also said she had been looking forward to spending more time on court after a mixed start to the tournament.

"On one side you don't want to spend too much time on the court in these tough conditions," Mauresmo told reporters.

"On the other hand I was playing some good tennis, much better than the first two matches I had, so maybe I wanted to keep it up," she said.

"But that's just the way it is. I just hope for her that it's not too bad and that she recovered well."

The muscular Frenchwoman struggled past China's Sun Tiantian 4-6, 6-2, 6-2 in the first round and again had to work hard as she beat compatriot Emilie Loit 7-6, 6-2 in round two.

Tournament medical staff checked Dutchwoman Krajicek's temperature and pulse as the 17-year-old sat courtside before deciding not to continue.

Her withdrawal came only minutes after officials invoked the tournament's extreme heat policy.

"I felt like I was going to throw up," Krajicek said.

"I just couldn't even see the ball because my eyes were burning very much. So it wasn't that good."

Mauresmo, runner-up in the 1999 Australian Open, will play 16th-seeded Czech Nicole Vaidisova in the fourth round, with either 12th seed Anastasia Myskina [Images] or seventh seed Patty Schnyder looming in the quarter-finals.

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