DEN BOSCH, (Netherlands), June 19: Top seed Kim Clijsters showed she is still struggling before next week’s Wimbledon as she scraped into the Ordina Open semifinals on Thursday.

The Belgian, French Open runner-up but still searching for her first title on grass, was pushed hard by a gutsy performance from Slovenian Tina Pisnik before winning 7-6 7-6.

Clijsters’ victory was revenge for her defeat by Pisnik at the same stage last year, but she was outplayed for much of the match.

Pisnik served and volleyed with aplomb, keeping Clijsters pinned to the baseline, and only a good tiebreak gave the Belgian the first set.

Clijsters should have wrapped up victory when she served for the match at 5-3 in the second set, but Pisnik broke back.

The Slovenian held for 5-5 and broke again to serve for the second set, only to be broken to 15 as the match went to a another tiebreak.

This time, Clijsters’ greater consistency was the key and she clinched her place in the last four when Pisnik netted an easy volley.

Fifth seed Nadia Petrova, a French Open semi-finalist, claimed a 6-4 3-6 6-2 victory over compatriot and fourth seed Elena Dementieva to set up a meeting with French Open champion Justine Henin-Hardenne or Ludmila Cervanova of Slovakia.

German Barbara Rittner followed up her victory over Amelie Mauresmo by thrashing another seed, number six Iroda Tulyaganova of Uzbekistan, 6-2 6-1.

She will play Clijsters in the semi-finals.

The men’s event was overshadowed by the news of Richard Krajicek’s retirement due to his continuing struggle with injuries.

The elbow injury that forced him to withdraw from Wimbledon this week, was the last straw for the Dutchmank, who will be remembered most for winning Wimbledon in 1996.

Dutch qualifier Dennis van Scheppingen did his best to lift the crowd but went down in three sets to seventh seed Arnaud Clement, the Frenchman winning 7-6 6-7 6-3.

He will play Fernando Vicente in the quarterfinals after the Spaniard rallied to beat German Lars Burgsmueller 4-6 6-4 6-4.

Top seed Jiri Novak had no trouble, cruising into the last eight with a 6-2 6-4 win over Krajicek’s conqueror Olivier Mutis.

Novak awaits the winner of the match between fifth seed Sebastian Grosjean and Czech Jan Vacek.

Results

Men: Second round

Jiri Novak (Czech Republic) bt Olivier Mutis (France) 6-2 6-4; Arnaud Clement (France) bt Dennis van Scheppingen (Netherlands) 6-7 (4-7) 7-6 (7-5) 6-3; Fernando Vicente (Spain) bt Lars Burgsmueller (Germany) 4-6 6-4 6-4; Jonas Bjorkman (Sweden) bt Taylor Dent (U.S.) - walkover, Dent back injury.

Women

Quarterfinals:

Kim Clijsters (Belgium) bt Tina Pisnik (Slovenia) 7-6 (7-4) 7-6 (7-4); Barbara Rittner (Germany) bt Iroda Tulyagnova (Uzbekistan) 6-2 6-1; Nadia Petrova (Russia) bt Elena Dementieva (Russia) 6-4 3-6 6-2