Hingis, Mauresmo, Clijsters in quarters

Switzerland's Martina Hingis in action during her fourth-round match against Australia's Samantha Stosur at the Australian Open in Melbourne, Australia, on Monday. PHOTO: AP

Proving power isn't everything, Martina Hingis took another step on the comeback trail yeterday, beating Australia's Samantha Stosur 6-1, 7-6 (8) to reach the Australian Open quarterfinals.

Hingis, coming out of retirement after three years, converted on her fourth match point, showing the same savvy that she used to win five Grand Slam titles.

The 25-year-old Swiss star next faces her biggest challenge so far against second-seeded Kim Clijsters, who has spent nearly all of her off-court time getting worked on by the trainers.

Clijsters no signs of the back and hip pain that has bothered her for the last week as she beat 15th-seeded Francesca Schiavone of Italy for a 7-6 (5), 6-4.

Hingis Stosur's strong ground strokes with an often-stunning blend of perfectly placed baseline shots, crisp volleys and soft drops that had the Australian dashing to the net for a pickup only to see the next shot lobbing over her head.

"I started off very well, I knew that I had to be right there from the start _ we both probably were very nervous," said Hingis. "I knew I couldn't give her any momentum."

Stosur, ranked 98th, seemed befuddled and almost on the verge of tears at times in the first set, giving the partisan crowd little to cheer about as she impatiently tried to hit winners.

In a sign of things to come, Hingis won the first point on a net court that dribbled over for a winner. She ran off the last five games of the first set, finishing it off in just 23 minutes.

But the second set was tougher, with Hingis getting the first break on a running forehand crosscourt pass that left Stosur virtually flat-footed. After that, both struggled with their serves, trading breaks four times in 12 games.

Hingis, a three-time Australian Open champion, had chances to serve for the match at 5-4 and 6-5, but was broken both times.

Stosur, feeding off the crowd's energy and finally showing the form that got her through three matches, refused to wilt.

Stosur ahead 5-2 in the tiebreaker. This time, it was Hingis' turn to rally. She ran off four straight points to set up her first match point that Stosur fended off with a 33-shot rally that ended when Hingis sent a forehand that landed at her feet well wide.

Stosur two more match points before Hingis finally finished it off on her fourth chance when Stosur netted a forehand, her 43rd unforced error.

"Toward the end I just don't want to remember the other finals I played here and lost in the second set," said Hingis, who blew four match points before losing to Jennifer Capriati in the 2002 final here.

Stosur a great fighter, I know she was the last Aussie standing, sorry for that, but I hope for your support in the next round."

Clijsters, another favorite of Australian crowds, overcame the stinging baseline power of Schiavone.

"I was a bit scared," Clijsters said of the nagging injuries that had her questioning whether she would even show up in Melbourne Park this year.

"I've probably been in the physio room more in the last week than in my life," she said. "Hopefully it'll pay off."

Clijsters trouble with her serve, with four double-faults, and had 43 unforced errors that could be attributed to staying off the court on her off-days.

"It's more important to rest than just be out there practicing," she said.

Fifth-seeded Nikolay Davydenko rallied from two sets and a break down to reach the men's quarterfinals and snap Dominik Hrbaty's run of five-set wins with a 4-6, 4-6, 6-4, 6-2, 6-3 victory.

After his loss on Monday, Hrbaty had spent a total of 13 hours and 57 minutes on court in four matches. The No. 12 seed from Slovakia was only the fourth man to play four consecutive five-set matches at one Grand Slam tournament.

American Robby Ginepri was the most recent, winning three times in five-setters at last year's US Open before losing the semifinal in five to Andre Agassi.

No. 21 Nicolas Kiefer had a 7-6 (4), 6-3, 6-3 win over Juan Ignacio Chela, who had ousted third-seeded Lleyton Hewitt in the second round.

Kiefer plays No. 25 Sebastien Grosjean, a 7-5, 6-2, 6-2 winner over fellow Frenchman Paul-Henri Mathieu.

WTA Championship winner Amelie Mauresmo cruised into the quarterfinals, committing only two unforced errors in a 6-1, 6-1 victory over 16-year-old Nicole Vaidisova.

Mauresmo plays Switzerland's Patty Schnyder, who beat 2004 French Open champion Anastasia Myskina 6-2, 6-1 in 55 minutes.

Myskina with her groundstrokes and had 32 unforced errors against only 13 for seventh-seeded Schnyder.

While Vaidisova was seeded 16th and dictated the pace of the match, the young Czech showed her inexperience on center court with 34 unforced errors to 14 winners and had her serve broken five times. Mauresmo won nearly twice as many points, 51-27.

Top-ranked Roger Federer, the overwhelming favorite in the men's draw, was playing Tommy Haas in the last match of the night.