MELBOURNE, Jan 25: Kim Clijsters dragged Martina Hingis back down to earth Wednesday, knocking her out of the Australian Open to join Roger Federer, Amelie Mauresmo and Nicolas Kiefer in the semi-finals. In the process the Belgian reclaimed the number one world ranking from Lindsay Davenport, who was sent packing in the quarter-finals on Tuesday.

Given that Hingis was a wildcard entry and ranked 349 in the world after a three-year injury layoff, it was an impressive performance as she took it to three sets before succumbing 6-3, 2-6, 6-4 in 1hr 42mins.

Clijsters’ win set up a semifinal on Thursday with French third seed Mauresmo, who was back in the dressing room in less than an hour against seventh seed Patty Schnyder, who collapsed 6-3, 6-0.

Federer came through a searching test from fifth seed Russian Nikolay Davydenko in four sets and will next tackle 21st seed Kiefer, who spent nearly five hours on court before downing Sebastien Grosjean of France, seeded 25.

Clijsters was full of praise for Hingis and jubilant about being number one.

Hingis said she was proud of herself, and eager for more big matches.

Federer, the top seed and world number one, was below his best against Davydenko, spraying too many errors but still managed to ensure a seventh successive Grand Slam semi-final, second only to Ivan Lendl’s 10.

“I always have tough matches against Nikolay and tonight was the same. He plays well on this surface and he definitely pushed me tonight,” said Federer after his 6-4, 3-6, 7-6 (9/7), 7-6 (7/5) win.

A pumped-up Kiefer was on court for 4hr 48mins against Grosjean, the longest match here in 15 years, in a volatile affair which he won 6-3, 0-6, 6-4, 6-7 (1/7), 8-6.

It wasn’t always pretty with Kiefer given two code violations for verbal abuse after raging at the Brazilian chair umpire Carlos Bernardes over disputed line calls.

But he held his nerve for the biggest win of his career, making a Grand Slam semifinal for the first time on his 35th attempt.

It was the longest match since Boris Becker and Omar Camporese played for 5hr 11min here in 1991, and was all the more gruelling for being played on another hot Melbourne day.

The match boiled over in the 12th game of the fifth set when Grosjean, seeded 25, called for the tournament supervisor after Kiefer threw his racquet at him while he was going for a volley.

But the point stood for Kiefer, and he knuckled down to produce a memorable victory. Kiefer later apologised but Grosjean wasn’t happy.

In contrast to their heated match, Mauresmo and Schnyder were a total mismatch, with the Swiss seventh seed at a level below the muscular Frenchwoman.

Mauresmo took the season-ending WTA Championships and has continued to build on that form, earning herself a crack at only her second final here as she attempts to break her Grand Slam duck.

She ran through the draw in 1999 only to be beaten in the final by Hingis.

Results:

Women’s (singles): Kim Clijsters bt Martina Hingis 6-3 2-6 6-4; Amelie Mauresmo bt 7-Patty Schnyder 6-3 6-0

Men’s (singles) quarterfinal: Roger Federer bt Nikolay Davydenko 6-4 3-6 7-6(7) 7-6(5); Nicolas Kiefer bt Sebastien Grosjean 6-3 0-6 6-4 6-7(1) 8-6.—Agencies