AP Sports Writer
MELBOURNE, Australia (AP) - Rafael Nadal limped out of the Australian Open complaining his leg was too sore to challenge Fernando Gonzalez in the quarterfinals. With Gonzalez stinging winners past him from both the forehand and backhand sides, though, even a fit Nadal might have struggled.
The 10th-seeded Gonzalez had 41 winners in a 6-2, 6-4, 6-3 upset over the second-seeded Nadal on Wednesday, earning him a semifinal spot along with top-ranked Roger Federer, Andy Roddick and Tommy Haas.
In the women's semifinals later Wednesday, the unseeded Serena Williams was to continue her unlikely quest for an eighth Grand Slam title. Limited to only four tournaments last year by recurring knee problems, Williams was not expected to be a serious contender at this year's Australian Open.
But she was one win away from the final, as was top-seeded Maria Sharapova - who reached the semis with a 7-6 (5), 7-5 win over Anna Chakvetadze, a fellow 19-year-old Russian.
Williams was to face 17-year-old Nicole Vaidisova of the Czech Republic in the first semifinal, followed by Sharapova against fourth-seeded Kim Clijsters.
Gonzalez, who will be playing in the semifinals of a Grand Slam tournament for the first time, will get a day off to watch Thursday's semifinal between defending champion Federer and sixth-seeded Roddick. Gonzalez will face Tommy Haas on Friday.
French Open champion Nadal was the only player to beat Federer at this stage of a tournament last year, doing it four times in finals. Federer was 91-1 against everyone else - his only other loss an upset to Andy Murray at Cincinnati.
It was a five-setter against Murray on Monday that Nadal thinks derailed his prospects of making the Australian Open final.
"I can't run a lot," he said Wednesday. "It was difficult to play one match like this, quarterfinals of one Grand Slam, with pain. If I am playing bad, well, you can go home and say disappointing. But today I just say, `Well, I can't do more. I try my best.'"
He called for a medical timeout in the third set and had to go to the locker room to remove his long, green shorts for treatment on his upper left leg and buttock.
Roddick is only 1-12 against Federer, but the 24-year-old American had match points against Federer at the Masters Cup last November and beat him in the final of an exhibition tournament at Kooyong on Jan. 14.
Gonzalez was hardly a contender until he beat local favorite Lleyton Hewitt in the third round and fifth-seeded James Blake in the fourth. The 26-year-old Chilean won 12 of 15 matches to end 2006 and made three finals - losing two to Federer.
He always had a powerful forehand but was too erratic with it, often criticized for swinging and missing too many times on big points. But since starting work last year with Larry Stefanki, who coached John McEnroe and helped Marcelo Rios and Yevgeny Kafelnikov reach No. 1, Gonzalez has been improving.
"I used to just hit, hit, hit, and maybe I win the point - now I have other strategies," he said. "I am playing great tennis. I can do great things in my game."
Gonzalez broke Nadal's serve twice in the first set, in the opening game of the second and twice again in the third, and only faced three break points. He had support from a scattering of Chilean supporters wrapped in flags and chanting in Spanish.
And he had growing support from the local crowd. Early in the third set, a man yelled: "You're the man, speedy."
Clijsters reached the women's semis by defeating Martina Hingis 3-6, 6-4, 6-3 on Wednesday. Hingis' comeback run from three years in retirement ended last year in a quarterfinal loss to Clijsters, who also beat her in the same stage at the French Open.
"It's great playing her and everything, but I don't want to see her in the quarterfinals ever again," said Hingis, who won three titles here and figured in six straight finals through 2002.
Clijsters has reached the semis in every trip she's made to Australia since 2002, and has bowed out to the eventual champion every time - losing three times in the semis and dropping the 2004 final to fellow Belgian Justine Henin-Hardenne.
Sharapova was brilliant at times and woeful at others against Chakvetadze, mixing 32 winners with 41 unforced errors and dropping serve twice in each set. She also was fined for coaching, after the chair umpire warned her for communicating with her father, Yuri, while serving at 2-2 in the second set.
Sharapova lost to Clijsters in an exhibition final at Hong Kong earlier in the month, but said she gained confidence from two wins late last year that ended a run of four losses against the Belgian.
"Obviously, she's a lot stronger than I am. Hands down to her. Other than that, I feel like I'm definitely on a closer level than I was a year ago," said Sharapova, the reigning U.S. Open champion.