Defeat a pain in the backside for limping Nadal

Andy Murray was not the only victim when he was beaten by Rafael Nadal in the fourth round of the Australian Open here on Monday night. The physical demands of their epic five-set match also took their toll on Nadal, who limped out of the tournament last night when he was brushed aside in three sets by Fernando Gonzalez.

Nadal, limping heavily after his 6-2, 6-4, 6-3 quarter-final defeat to the hard-hitting Chilean, felt the injury to his left leg only after his win over Murray. "I thought I was just tired after playing a very tough match, but I have a lot of pain walking now and I think it's more than tiredness," he said. "I couldn't run a lot." Pointing to his left buttock, he said the worst of the pain was "in my famous arse".

It was a disappointing end for the Spaniard, who after six months without reaching a final was starting to look again like the player who so dominated the last two clay-court seasons. He said he would have a scan on his leg after returning to Spain tomorrow.

Gonzalez was not the sort of man to face when only half-fit. The No 10 seed used to be a loose cannon, spraying his thunderous forehand all around the court, but he now saves his fire for the right moment. Larry Stefanki, his coach, has taught him to slice more and, as a consequence, the 26-year-old has been one of the game's most improved players of the last six months.

He said he was playing the best tennis of his career. "Before I used to hit, hit, hit and sometimes I won the point and sometimes I lost it," he said. "Now I'm trying to find the right opportunity and stay a little bit calm, because my hitting can be a bit crazy sometimes."

Gonzalez will play his first Grand Slam semi-final tomorrow against Germany's Tommy Haas, who reached the last four here in 1999 and 2002. The No 12 seed pulled off the day's other major surprise when he beat Nikolai Davydenko, the No 3 seed, 6-3, 2-6, 1-6, 6-1, 7-5.

Roger Federer was due to play Andy Roddick in the other men's semi-final today after the women's semi-finals, in which Serena Williams was facing Nicole Vaidisova and Kim Clijsters was playing Maria Sharapova.

Clijsters yesterday overcame her good friend, Martina Hingis, 3-6, 6-4, 6-3 for the second successive year at this stage while Sharapova reached her eighth semi-final out of the last nine Grand Slam events by beating her fellow Russian, Anna Chakvetadze, 7-6, 7-5.

While Clijsters, 23, is on a farewell world tour, having decided to retire at the end of the year, Hingis, 26, is at the start of the second season of her comeback after a three-year break from the game. The Swiss climbed to No 7 in the world rankings last year, but since beating Sharapova in Tokyo last February she has lost all 11 of her matches against the big four of Sharapova, Clijsters, Amélie Mauresmo and Justine Henin-Hardenne.

This was her fourth loss out of four to Clijsters over the last year and she said it was the most disappointing. The Belgian looked out of sorts and made 62 unforced errors, but Hingis failed to build on her winning start.

Nevertheless the former world No 1 remains a refreshingly different player compared with the conveyor-belt youngsters who simply whack the ball as hard as they can from the baseline. The Swiss constantly varies the pace and angle of her strokes and there is arguably no better exponent of the drop shot.

"Today I always tried to give her a different look at the ball and I think that's why she made so many errors," Hingis said. "I also anticipated well. She was missing because somehow I was already waiting for her shots. That's my game. That's how I win my matches. That's why I was up early in the second set, with a set behind my back."

Although Hingis said she sometimes regretted not having a killer shot to finish off points at the end of physically demanding matches, she believes she is a better player than she was during the years when she reached six successive Australian Open finals from 1997.

Her problem is that the fitness and strength of opponents have risen sharply. She also identifies one major mental weakness. "Before I was more fearless," she said. "Today I'm too tentative. I don't just say: 'OK, go for it.' I'm too nice."

Chakvetadze is not dissimilar to Hingis. The 19-year-old is a thoughtful constructor of points and her intelligent play and persistence in retrieving seemed to unsettle Sharapova, who described her own performance as "a bit scratchy". Nevertheless, there is little substitute for power. "She was hitting the ball so hard," Chakvetadze said. "In the warm-up I thought she was going to kill me."

Chakvetadze led 4-2 in the first set but a combination of nerves and a shoulder injury contributed to her downfall. "My shoulder was tight in the morning," she said. "I should have called the trainer earlier."

Sharapova's father, Yuri, who has been regularly criticised for coaching from the sidelines, earned his daughter a code violation. The umpire told Sharapova the warning was for coaching between points, though the US Open champion insisted: "I didn't see anything. I didn't even look at him."

* Justine Henin-Hardenne confirmed yesterday that she was separating from her husband, Pierre-Yves, after five years of marriage. The world No 1, who withdrew from the Australian Open, will make her comeback in Paris next month.