Martina Hingis has quickly quieted her doubters.
The former world No. 1, coming back from a three-year retirement, ripped through her third consecutive opponent yesterday to advance to the fourth round of the Australian Open on a day that the heat was some players' worst opponent.
As good as Hingis was, fellow Swiss Roger Federer was virtually untouchable in beating 30th-seeded Max Mirnyi, who played well enough to beat most players but still was blitzed 6-3, 6-4, 6-3.
Top-ranked Federer had 48 winners, committed only 10 unforced errors -- just one in the second set -- and dropped only 13 points in 14 service games.
Seeking his seventh Grand Slam title and second here, he withstood Mirnyi's blistering first serves, which reached 220kmph, breaking him four times. With Mirnyi serving at 3-5 in the third set, Federer finished it off on his third match point with a forehand service return winner.
Looking like a big cat looking to pounce at every opportunity, the 1.96m Mirnyi charged the net 102 times. But it only amounted to target practice for the relaxed Federer, who whipped passing shots from both sides with apparent ease.
There were questions about Hingis' fitness coming into the tournament. But she looked fresh as she took the court for a late-morning match, committing only 12 unforced errors in a 6-4, 6-1 victory in 65 minutes over Iveta Benesova, who suffered as temperatures rose.
"It wasn't as cruel, brutal" as later in the day, Hingis said. "Thank God she felt it more than I did."
Hingis has dropped only 10 games in her three matches, looking almost as dominating as when she won three of her five Grand Slams here.
"I don't think I played my best tennis today," she said. "But as long as you win, it's always good. Always room to improve for the next match."
That will be against unseeded Australian Samantha Stosur, with a possible quarterfinal match looming against second-seeded Kim Clijsters.
Clijsters had a 6-1, 6-2 win over Italian Roberta Vinci in 44 minutes, showing no obvious signs of the hip and back problems that have been bothering her.
For the second consecutive day, the tournament invoked the extreme heat policy that calls for play to be suspended on outside courts after matches already under way were completed. The roofs were closed on Rod Laver Arena and Vodafone Arena.
Temperatures exceeded 40?C -- and were perhaps 10 degrees higher on court. Today's forecast calls for even hotter conditions before a cooler change next week.
Third-seeded Amelie Mauresmo was leading Michaella Krajicek 6-2 when the 17-year-old Dutch player withdrew because of heat stress.
"I felt like I was going to throw up ... I couldn't even see the ball because my eyes were burning," Krajicek said after having an ice bath to cool down.
One player who wasn't complaining was 12th-seeded Dominik Hrbaty. Known for his fitness, he won his third consecutive five-set match, rallying from an 0-3 deficit in the fifth against No. 23 Igor Andreev of Russia.
"I was tired already going to the match," he said. "If we would play inside, I think I wouldn't win with Andreev. I think it's more mental, how much you will be able to push yourself."
Hrbaty, who already has spent 10 1/2 hours on court in singles, later lost a three-set men's doubles match. He next faces fifth-seeded Nikolay Davydenko, who ousted the last Australian men's hope Nathan Healey.