Wimbledon, July 3:

Defending champion Amelie Mauresmo lost in the fourth round at Wimbledon on Tuesday, struggling with her serve throughout and falling to Nicole Vaidisova 7-6 (6), 4-6, 6-1 in a match interrupted by rain three times.

Mauresmo, who won her first two Grand Slam titles last year, had 14 double-faults and 37 unforced errors. The fourth-seeded Mauresmo held three set points when she led 6-3 in the tiebreaker but then lost the next five points. After winning the second set, she fell behind 3-0 in the third and was broken again in the sixth game, allowing the 18-year-old Vaidisova to serve out the match.

Mauresmo was sidelined earlier this year following an appendectomy in March and had a groin problem that contributed to an early exit at the French Open. Vaidisova reached the quarter-finals for the first time at the All England Club. The No 14-seeded Czech reached the semi-finals at last year’s French Open and this year’s Australian Open.

Vaidisova will play No 6 Ana Ivanovic in the quarter-finals. The Serb held on to beat Nadia Petrova 6-1, 2-6, 6-4 in a match interrupted by rain four times. No 3 Jelena Jankovic also was upset, losing to No 18 Marion Bartoli of France 3-6, 7-5, 6-3. Bartoli will face Michaella Krajicek in her first Grand Slam quarter-final.

Also, 2004 US Open champion Svetlana Kuznetsova reached the quarter-finals beating 16-year-old Tamira Paszek of Austria 6-3, 6-2. Kuznetsova will face either Venus Williams or Maria Sharapova in the next round.

On the men’s side, 2003 French Open champion Juan Carlos Ferrero reached the quarter-finals for the first time beating Janko Tipsarevic 7-5, 6-3, 7-6 (5). Lleyton Hewitt, the 2002 Wimbledon champion, reached to the fourth round beating Guillermo Canas 6-4, 3-6, 6-3, 6-4, and Nikolay Davydenko advanced by defeating Gael Monfils 6-3, 7-5, 6-3.

This year’s tournament has been hampered by rain in seven of its first eight days. Matches on Centre Court and Court No 1 started two hours earlier than usual because of the backlog of matches.

On Monday, Serena Williams decided to keep on going despite a painful calf strain that left her screaming and writhing behind the Centre Court baseline. A rain delay of nearly two hours bought her a little time to recover and regroup. She won the third set to beat Daniela Hantuchova 6-2, 6-7 (2), 6-2. The gallant, bizarre victory advanced Williams to the quarter-finals, where she’s scheduled to face top-ranked Justine Henin — if she’s able.