Melbourne, Australia ? Wimbledon champion Maria Sharapova overcame the heat and U.S. Open winner Svetlana Kuznetsova 4-6, 6-2, 6-2 Tuesday to advance to the semifinals at the Australian Open.

Kuznetsova failed to hold any of her last eight service games after winning the first set and gave the 17-year-old Sharapova a match point with a double-fault, her fourth of the all-Russian quarterfinal.

Sharapova, whose screeching increased with every shot, whipped a running forehand crosscourt winner to close out the match in 2 hours, 17 minutes. She dropped her racket and flung both arms in the air.

“I need a wheelchair right now,” said Sharapova, on the verge of exhaustion. “Just mentally, I tried to tough it out.”

Both players struggled in Melbourne’s hot summer conditions, taking a 10-minute break between the second and third sets and putting ice packs and wet towels on their necks.

The temperature at the start of the match was 87 degrees, and rose to 91 degrees.

“It was so hot — on the court it’s very, very hot,” said Sharapova. “I just try to concentrate on what I have to do … block it out. But it was one of the toughest (matches) of my life.”

Kuznetsova finished with 53 unforced errors and got less than half of her first serves into play, giving Sharapova plenty of chances to pounce on the second serves.

Sharapova made almost half of her 37 unforced errors in the last set.

Serena Williams, meanwhile, shrugged off the searing heat and beat second-ranked Amelie Mauresmo 6-2, 6-2 Tuesday to set up a semifinal showdown against Sharapova.

On Monday, Venus Williams’ Grand Slam drought continued. Facing three match points, she stumbled chasing a ball, and her off-balance forehand flopped into the net, giving Alicia Molik a 7-5, 7-6 (3) upset in the fourth round.

“I feel like that was one I definitely should have won. I just was off of my rhythm,” the eighth-seeded Williams said. “I definitely didn’t produce my best tennis, that’s for sure.”

Two other top women lost Monday: French Open champion Anastasia Myskina and No. 6 Elena Dementieva, the runner-up at the French Open and U.S. Open. In men’s action, No. 2 Andy Roddick, No. 3 Lleyton Hewitt, No. 9 David Nalbandian and No. 26 Nikolay Davydenko moved into the quarterfinals.