Eighth-seeded Justine Henin-Hardenne upset No. 1 Lindsay Davenport 2-6, 6-2, 6-3 yesterday to advance to the Australian Open semifinals.
The loss may cost Davenport, who lost the final here last year to Serena Williams, the top ranking that she has held since Oct. 24. Kim Clijsters or Amelie Mauresmo, who face quarterfinal matches today, both have a shot at becoming the new No. 1.
The possible slippage in her ranking doesn't worry Davenport.
"It's not up in my priority list," Davenport said. "My whole goal is just to get better. I'll be playing fewer tournaments this year, so it's inevitable."
Henin-Hardenne next faces fourth-seeded Maria Sharapova, who overcame troubles with the gusty winds in Rod Laver Arena and saved two set points in an error-filled tiebreaker before ousting sixth-seeded Nadia Petrova 7-6 (6), 6-4.
"It was definitely not easy," said Sharapova, the 2004 Wimbledon champion. "It was a miracle when someone held serve."
The wind also played havoc with the serves of Davenport and Henin-Hardenne, who combined for 13 service breaks and 18 double faults.
With Oscar-winning actress Charlize Theron watching, Henin-Hardenne had her serve broken all four times in the first set. After her fourth double fault on break point gave Davenport a 5-2 lead, Henin-Hardenne angrily whacked the ball into the net.
Davenport returned the favor, double faulting on set point to level the match at 1-1.
Henin-Hardenne, the reigning French Open champion and the 2004 winner here, finally got the break that really mattered, converting on her fourth opportunity with Davenport serving at 2-3 in the third set.
She withstood three double faults in her last two service games, finishing off the match when Davenport sent a backhand service return long.
Demonstrating her refuse-to-lose mentality, Sharapova survived two set points in an error-filled tiebreaker after Petrova twice served for the first set.
Petrova had 12 double faults, including one serving for the first set at 6-5, another facing set point in the tiebreaker and one to surrender another break at 1-3 in the second.
It was a testy match. Petrova has clashed in the past with Sharapova's father, Yuri, who loudly encourages his daughter.
Sharapova looked in his direction frequently, for what she called "inspiration" and "motivation."
"I just tried to ignore him completely," Petrova said. "I didn't look at his side once."
In tears at times and spiking her racket, a frustrated Petrova finished with 49 unforced errors.
"I just feel like I simply gave it away," said Petrova, who added that she needs to work on her toughness.
"It couldn't be a better present," she said.
Masters Cup champion David Nalbandian reached the semifinals -- completing a full set at the majors -- when he overwhelmed veteran Frenchman Fabrice Santoro 7-5, 6-0, 6-0.
The fourth-seeded Nalbandian was down a break in the first set, but took the last 14 consecutive games.
Santoro, 33 and playing in the quarterfinals for the first time in 54 majors, never had a game point after holding at 5-5 in the first.
"After that first set, he just gave me a lesson," Santoro said. "I try many things, but he has the answer all the time. He just played great tennis, wonderful."
Santoro had Nalbandian sprinting from side to side, net to baseline, chasing drop shots, volleys and lobs until the 24-year-old Argentine got his ground strokes working and started passing him on both sides.