U.S. Open champion Sam Stosur suffered a second-round upset, while former world No. 1 Caroline Wozniacki was sent packing in round one at The Championships, Wimbledon.

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 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 former world No. 1 star Kim Clijsters in the second round last year at the French Open.

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 roof 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 had to save four set points just 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 AEC.

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.

Meanwhile, 15th-seeded Sabine Lisicki overcame loud Serb Bojana Jovanovski 3-6, 6-2, 8-6. The German slugger Lisicki reached the Wimbledon semis a year ago.

Afterwards, Lisicki said Jovanovski makes more on-court noise than Maria 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."

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 promising British favorite Heather 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 first-round wins came for Ukrainian Kateryna Bondarenko, Belarusian Olga Govortsova and France's Alize Cornet.

Rain delayed play for several hours on the outside courts on Wednesday.