Outgoing Belgian star Kim Clijsters reached the third round, while reigning U.S. Open champion Sam Stosur suffered a second-round upset and former world No. 1 Caroline Wozniacki was sent packing in round one at The Championships, Wimbledon.

The 29-year-old Clijsters disposed of fellow non-seed Andrea Hlavackova of the Czech Republic 6-3, 6-4 in 65 minutes on a roof-enclosed Centre Court. Clijsters did not allow even one break-point chance on a rainy Day 3.

The former world No. 1 and four-time Grand Slam champion Clijsters is appearing in her last Wimbledon event, as she will retire from tennis following this year's U.S. Open.

She will meet Russian Vera Zvonareva in round three.

Promising 21-year-old Dutchwoman Arantxa Rus knocked out the fifth-seeded Aussie Stosur 6-2, 0-6, 6-4 on Court 1 at the All England Lawn Tennis Club. Stosur has only ever reached the third round once in 10 tries on the grass in this London suburb and has suffered five opening-round losses at tennis' most prestigious event.

Rus shocked Clijsters in the second round last year at the French Open.

Stosur is the highest seed to exit the women's draw thus far.

Aggressive Austrian Tamira Paszek toppled the seventh-seeded Wozniacki 5-7, 7-6 (7-4), 6-4 under the roof at Centre Court. The match started on Tuesday and was suspended because of rain, and the bout was interrupted by rain once again on Wednesday, prompting tournament officials to close the expensive translucent covering on Day 3.

Paszek served for the match leading 5-3 in the third set, only to see Wozniacki break to stay alive. But the Dane was promptly broken herself in the next game when the Austrian converted on her first match point with a blistering forehand winner, her 54th winner of the high-quality 3-hour, 12-minute bout.

The former U.S. Open runner-up Wozniacki wasted two match points in the second set and had to save four set points in order to win the first set on Wednesday.

This marks only the second time that Wozniacki has lost in the first round of a major (20-2). She has never reached the quarterfinals at Wimbledon.

The 21-year-old Paszek was a Wimbledon quarterfinalist last year and has now won five of her last six matches at the AELTC.

Paszek, fresh off her grass-court title at Eastbourne, has now won her last six matches overall, this after winning only two WTA matches all year prior to last week. She said beating Wozniacki was "an amazing feeling."

Top-seeded former Wimbledon champion and 2011 runner-up Maria Sharapova was leading Bulgarian Tsvetana Pironkova 7-6 (7-3), 3-1 in a second-rounder on Court 1 when play was called because of darkness. The capable Pironkova reached the Wimbledon semifinals two years ago and the quarterfinals here last year.

The match will resume on Thursday.

The world No. 1 Sharapova is trying to become the first woman to win the French Open and Wimbledon in the same year since Serena Williams turned the trick 10 years ago. Sharapova captured her first-ever French Open title three weeks ago to become the 10th woman in tennis history to secure the career Grand Slam.

The 25-year-old Sharapova captured her lone Wimbledon championship as a 17- year-old in 2004 and was last year's runner-up here to powerful Czech lefthander Petra Kvitova. The Russian star has appeared in three of the last four major finals (1-2).

Third-seeded Agnieszka Radwanska posted a second-round win by blasting Russian Elena Vesnina 6-2, 6-1. The steady Pole will meet heavy British crowd favorite Heather Watson on Friday.

Meanwhile, Romanian Sorana Cirstea upended 11th-seeded former French Open champion Li Na of China 6-3, 6-4; the 12th-seeded 2010 Wimbledon and U.S. Open runner-up Zvonareva held off Spaniard Silvia Soler-Espinosa, 6-1, 3-6, 6-1; 15th-seeded German Sabine Lisicki overcame loud Serb Bojana Jovanovski 3-6, 6-2, 8-6; and 17th-seeded Russian Maria Kirilenko drilled Spaniard Lourdes Dominguez Lino 6-1, 6-2 in the second round.

Afterwards, last year's Wimbledon semifinalist Lisicki said Jovanovski makes more on-court noise than Sharapova and Victoria Azarenka, who are both well known for their screams and wails.

"It was distracting," Lisicki said. "You usually hear the sound of the ball but I couldn't hear it because of her grunting. That's why we have the hindrance rule.

"It was completely different from Sharapova or Azarenka but off-putting as well. Grunting is part of the game but it shouldn't be off-putting and be an advantage for the one who is doing it."

Thirtieth-seeded Chinese Peng Shuai reached the round of 32 with a 7-6 (7-4), 6-3 victory over Japan's Ayumi Morita.

Rising American Sloane Stephens reached the third round with a 7-6 (8-6), 4-6, 6-3 upset of 23rd-seeded Czech Petra Cetkovska, while the promising Watson moved on with a 6-1, 6-4 second-round victory over American Jamie Hampton.

Tenth-seeded French Open runner-up Sara Errani of Italy reached the second round with a 6-1, 6-3 victory over American Coco Vandeweghe.

In other first-round action involving seeds, Czech veteran Klara Zakopalova ousted No. 13 Slovak Dominika Cibulkova 6-4, 6-1, No. 14 Serb Ana Ivanovic got past Spaniard Maria Jose Martinez Sanchez 6-3, 3-6, 6-3, and No. 22 German Julia Goerges grounded Israeli Shahar Peer 6-2, 6-2. Ivanovic is a former world No. 1 and French Open champ.

Additional second-round wins came for Italian Camila Giorgi and Taiwan's Su- Wei Hsieh, while other first-round wins came for Ukrainian Kateryna Bondarenko, Belarusians Olga Govortsova and Anastasiya Yakimova, and France's Alize Cornet.

Rain delayed play for several hours on the outside courts on Wednesday and four second-round matches were suspended or postponed.

In some other second-round action here on Thursday, the second-seeded former No. 1 and reigning Australian Open champion Azarenka will meet Swiss Romina Oprandi, a fourth-seeded and reigning Wimbledon champion Kvitova will battle Brit Elena Baltacha, and a sixth-seeded Williams will be opposed by Hungarian Melinda Czink. The 2011 U.S. Open runner-up Williams owns 13 major singles titles, including four here at the AELTC.