BEIJING, Aug 10: The opening day of the Olympic tennis turned into a nightmare for the organisers as rain washed out most of the schedule and women's top seed Ana Ivanovic pulled out with a swollen thumb.

Just nine of Sunday's slated 45 matches survived the torrential downpours and thunderclaps that left fans frustrated and volunteers mopping the courts with towels.

Men's top seed Roger Federer and a host of other big names did not even make it on to court.

American James Blake was one of the few to work up a sweat, beating Australian left-hander Chris Guccione 6-3, 7-6 on Centre Court. Compatriot Serena Williams was not so lucky.

Fourth seed Williams, making her debut in the Olympic singles having won the doubles with sister Venus in 2000, was leading 6-3 2-1 against Olga Govortsova of Belarus when rumbling thunder had her casting her eyes anxiously to the heavens.

Minutes later the players were dashing for cover.

After the start of play was delayed by two hours in the morning, the rain returned for good just before 4:30pm and play was postponed at 7:00 pm

Organisers are confident they can make up the backlog of matches on Monday, although showers are forecast.

Ivanovic, who will lose her world No 1 spot on Monday to fellow Serb Jelena Jankovic, was clearly emotional when she explained her withdrawal to reporters.

“This is one of the hardest moments of my career and one of the hardest decisions I've had to take,” 20-year-old Ivanovic told a news conference at the Olympic Tennis Centre.

Ivanovic said she had not been able to practise for 10 days but had travelled to China in the hope the injury to her thumb joint would recover.

“I've tried everything to recover, laser treatment, magnetic treatment ... I've had more treatments in 10 days than I've had in my life,” she said.

Blake needed little more than an hour to beat Guccione on his Olympic debut.

Fernando Gonzalez of Chile, the reigning Olympic doubles champion, made it into the second round with a 6-4, 6-4 defeat of China's Sun Peng. Fourth seed Nikolay Davydenko of Russia beat Ernests Gulbis of Latvia 6-4, 6-2.

Four women's singles matches were completed, with wins for Italian Francesca Schiavone and Australia's Samantha Stosur.

Results (prefix number denotes seeding):

Men’s singles:

First round: Guillermo Canas (Argentina) bt Frederic Niemeyer (Canada) 3-6, 4-2 — Niemeyer retired; Tomas Berdych (Czech Republic) bt Yu Xin-yuan (China) 6-1, 6-2; 4-Nikolay Davydenko (Russia) bt Ernests Gulbis (Latvia) 6-4, 6-2; 12-Fernando Gonzalez (Chile) bt Sun Peng (China) 6-4, 6-4; 8-James Blake (US) bt Chris Guccione (Australia) 6-3, 7-6 (7-3).

Women’s singles:

First round: Samantha Stosur (Australia) bt Sara Errani (Italy) 6-3, 6-2; Francesca Schiavone (Italy) bt Akgul Amanmuradova (Uzbekistan) 6-4, 6-2; Caroline Wozniacki (Denmark) bt Selima Sfar (Tunisia) 6-4, 6-1; Tsvetana Pironkova (Bulgaria) bt Marta Domachowska (Poland) 6-3, 6-4.—Reuters