WIMBLEDON, England (AP) -- Returning to the court where she won her first Grand Slam championship a year ago, Petra Kvitova overcame a shaky start and a late rain delay Tuesday to open her Wimbledon title defense with a 6-4, 6-4 victory over Akgul Amanmuradova.
Four-time champion Serena Williams, meanwhile, returned to the same Court 2 where big sister Venus was upset a day earlier and restored family pride by beating Barbora Zahlavova Strycova of the Czech Republic 6-2, 6-4.
The fourth-seeded Kvitova fell behind 3-0 and 4-1 in the first set on Centre Court before running off seven straight games to take command against the 96th-ranked player from Uzbekistan.
After Kvitova squandered a match point at 5-3 in the second set, play was suspended and the covers rolled onto the court - the first rain break of the tournament.
When play resumed half an hour later, it took just three minutes to wrap up the match. After Amanmuradova won the first two points to hold for 5-4, the Czech player closed it out at love, hitting a service winner, two aces and forcing a backhand error.
"It was unbelievable to come back here as the defending champion," said Kvitova, who beat Maria Sharapova in last year's final. "In the beginning I think I was nervous - first match on the grass it's always difficult to know what you can expect. I had a lot of mistakes and then I tried to play my game and go forward."
The 6-foot-3 Amanmuradova pushed Kvitova with her big serve, but lacked the consistency on her ground strokes and has now lost in the first round of all five of her Wimbledon appearances.
Following Kvitova on Centre Court was two-time champion Rafael Nadal, and he found himself in an early hole just as she had. Nadal was down 4-0 in the opening set, but roared back to beat Brazilian left-hander Thomaz Bellucci 7-6 (0), 6-2, 6-3. The Spaniard closed the match with an ace down the middle, his sixth of the day.
Nadal, coming off his record seventh French Open title, broke six times and had 35 winners and 18 errors. Having lost in last year's final to Novak Djokovic, he is bidding for a 12th Grand Slam title.
"I'm very happy to be back on the best court in the world and winning," Nadal said. "It's fantastic for me, but I have to improve a lot for the next round."
Play was later suspended for the day because of rain and poor light, leaving several matches unfinished. Three-time finalist Andy Roddick was leading Britain's Jamie Baker 7-6 (1), 4-2 on Court 1 when the covers came on. Tenth-seeded Sara Errani, runner-up at the French Open earlier this month, was holding match point in the second set when her match against American qualifier Coco Vandeweghe was halted.
Williams ground out a shriek-filled win over 62nd-ranked Zahlavova Strycova, a day after five-time champion Venus lost her first-round match on the same court in straight sets to Elena Vesnina.
"It always has some sort of an effect," Serena said. "I always want to play even better if she's out of the tournament."
It was clear how much the match meant to the animated Serena, who screamed loudly in frustration after losing points and shouted "Come on!" and pumped her fist after winning big points.
Williams seemed to be in control after going up 3-1 and then 5-3 in the second set. But, serving for the match, she was broken back for 5-4. Williams broke again in the next game, letting out another scream after Zahlavova Strycova struck a forehand long on the second match point.
"Definitely a little relief," she said. "I was letting out a lot of cries. I was happy to get through that."
Williams, who extended her record to 13-0 in first-round matches at Wimbledon, finished with 24 winners and 12 unforced errors, compared to 17 winners and 13 errors for her opponent.
Last year, Williams questioned why tournament organizers assigned her and her sister to play on Court 2 rather than Centre Court, considering they have won a combined nine singles titles at Wimbledon. On Tuesday, she declined to address the issue.
"I can't even talk about it," she said. "I'm over it. I don't care to talk about it."
Also advancing to the second round in straight sets was No. 2 Victoria Azarenka. The Australian Open champion who beat American Irina Falconi 6-1, 6-4. Azarenka reached the semifinals at Wimbledon last year before losing to Kvitova.
In men's play, fourth-seeded Andy Murray of Britain swept to a 6-1, 6-1, 6-4 win in gloomy conditions on Centre Court over Nikolay Davydenko, a former No. 3-ranked player from Russia who has dropped to No. 47 and lost in the first round for the second year in a row. Murray, who has lost in the semifinals here the past three years, is still carrying the pressure of trying to become the first British player to win the men's title since Fred Perry in 1936.
Fifth-seeded Jo-Wilfried Tsonga took apart 2002 champion Lleyton Hewitt, 6-3, 6-4, 6-4. The Frenchman, who beat six-time champion Roger Federer last year to reach the semifinals, broke the Australian once in each set and never lost serve.
Hewitt has slipped to 202nd in the rankings and needed a wild card for his 14th straight appearance at the All England Club. Tsonga was too powerful, racking up 61 winners to the Australian's 12. It was Hewitt's first opening-round loss here since 2003.
Hewitt was one of four Australians in the men's draw, and all bowed out in the first round. It marks the first time since 1938 that no Australian men have reached the second round at Wimbledon.
Playing his first match since having a medical procedure on his heart, 10th-seeded Mardy Fish of the United States served 24 aces and beat Ruben Ramirez-Hidalgo of Spain 7-6 (3), 7-5, 7-6 (1) to reach the second round.
The 30-year-old Fish, who reached the quarterfinals last year, hadn't played a competitive match in 2 1/2 months after having an accelerated heartbeat. He played attacking, serve-and-volley tennis and piled up 63 winners against Ramirez-Hidalgo - at 34, the oldest man in the field.
Afterward, Fish canceled his news conference, because "he's not feeling well," ATP spokesman Nicola Arzani said.
Jarkko Nieminen ousted 14th-seeded Feliciano Lopez of Spain, 7-6 (4), 3-6, 7-6 (5), 6-4.
In early women's play, No. 12 Vera Zvonareva completed a 2-6, 7-6 (3), 6-4 win over Germany's Mona Barthel in a match that had been suspended by darkness at one set apiece on Monday.
Francesca Schiavone, the 24th-seeded Italian, came from behind to overcome 18-year-old British wild card Laura Robson 2-6, 6-4, 6-4. Schiavone, the 2010 French Open champion, received medical treatment after the first set for an apparent muscle problem. She was down 2-3 and 0-40 in the second set but saved the three break points and turned the match around against the 2008 Wimbledon junior champion.
In a men's match between two rising stars, 21-year-old Belgian wild card David Goffin - who reached the fourth round of the French Open and took a set off Federer - rallied from a set down against 19-year-old Bernard Tomic to beat the 20th-seeded Australian, 3-6, 6-3, 6-4, 6-4.