Lindsay Davenport survived an injury scare on Sunday to reach the quarter-finals of the Australian Open for the ninth time in her career.
The world number one aggravated a sprained left ankle against Russia's 14th seed Svetlana Kuznetsova but limped to a 6-2, 6-4 win on another scorching day at Melbourne Park.
Tournament organisers invoked the extreme heat rule for the third day in a row, closing the roofs over the two main courts as the mercury soared towards a forecast 43 degrees Celsius (109 Fahrenheit).
Eighth seed Justine Henin-Hardenne underlined her standing as favourite with a crushing 6-0, 6-3 defeat of Virginia Ruano Pascual. The Belgian will play Davenport on Tuesday for a place in the semi-finals.
Sixth seed Nadia Petrova was also in scintillating form, thrashing unseeded Russian compatriot Elena Vesnina 6-3, 6-1 to advance against either fourth seed Maria Sharapova or 17th seed Daniela Hantuchova of Slovakia.
Davenport began brilliantly against Kuznetsova, racing through the opening set in just 18 minutes and opening up a 3-0 lead in the second.
But the Californian suddenly looked in trouble when she jammed her heavily strapped ankle, then lost the next four games after having it re-taped.
However, she regained her composure as the errors started to creep into Kuznetsova's game, winning the last three games to seal victory in an hour.
"I knew that if it wasn't in two sets, that my chances were significantly reduced so I was trying very hard," Davenport told a news conference.
"I'm still in the tournament. I still have a chance to get it better. It's just one of those things where you shake your head about it in disbelief."
OUTSTANDING FORM
Henin-Hardenne was in outstanding form against Ruano Pascual, outclassing the unseeded Spaniard to continue her unbeaten run in Australia to 18 matches over three years.
Henin-Hardenne won the title in 2004 but was unable to defend it last year because of injury. She won the French Open on her return to Grand Slam tennis but is making another comeback after more health problems at the end of last season.
"I've had a lot of comebacks in the last two years," she said.
"I can do good comebacks. But it takes a lot of energy.
"I will enjoy being here in the quarters again. I think that's pretty amazing after four months off."
Petrova, twice a French Open semi-finalist, profited from a string of errors by inexperienced 19-year-old Vesnina, who was playing in her first Grand Slam tournament.
Vesnina produced a sloppy 35 unforced errors in the 62-minute match, the final one coming when she lamely netted a backhand on Petrova's first match point.
