Rafa, Petra battle thru'

Defending champion Petra Kvitova overcame early nerves to reach the Wimbledon second round on Tuesday.

Kvitova pulled off a 6-4, 6-4 win over Akgul Amanmuradova of Uzbekistan, but the 22-year-old did it the hard way.

In the men's single's, former champion Rafael Nadal also survived an early scare to kick off his bid for a third Wimbledon title with a 7-6 (7/0), 6-2, 6-3 victory over Brazil's Thomaz Bellucci in the first round.

The winner in 2008 and 2010 was 4-0 down in the first set before rallying back against the spirited young Brazilian. Nadal will face Ivan Dodig or Lukas Rosol for a place in the last 32.

Earlier, Kvitova fought back from 3-0 and 4-1 down in the first set before seeing off Amanmuradova, who has now lost all her five first round appearances at the tournament.

Once Kvitova had reeled off seven successive games to take the first set and lead 2-0 in the second, she was comfortably in control, managing to shrug off a brief rain delay 5-3 and deuce in the second set.

Meanwhile, American hopes, which were so badly bruised by the opening day exits of five-time champion Venus Williams and big-serving John Isner, were boosted by Serena Williams, Mardy Fish and Bryan Baker.

Serena Williams reached the second round with a 6-2, 6-4 win over Barbora Zahlavova Strycova of the Czech Republic.

Fish made a winning return to tennis in his first match following a procedure to address a frightening heart scare.

The world number 12 beat Spain's Ruben Ramirez-Hidalgo 7-6 (7/3), 7-5 7-6 (7/1) and looked comfortable moving around the court.

It was his first tournament appearance since April, when, as top seed, he fell at the first hurdle in Houston.

Suffering from arrhythmia, he then underwent surgery to correct faulty wiring in his heart.

Fish said the had made it hard for him to sleep and his heart felt like it was going to burst out of his chest.

Baker, who lost six years of his career to an assortment of injuries and underwent five operations, clinched a first ever win at Wimbledon, beating Portugal's Rui Machado 7-6 (7/2), 6-4, 6-0.

Lleyton Hewitt's 10th anniversary party of his 2002 Wimbledon title was gatecrashed by French fifth seed Jo-Wilfried Tsonga who cruised to a 6-3, 6-4, 6-4 first round win.

The 27-year-old reached the second round of the French Open last month in what was his first Grand Slam appearance since the 2005 US Open.

Bernard Tomic admits he has paid the price for getting lazy as the Australian teenger's slump continued with a surprise 3-6, 6-3, 6-4, 6-4 defeat against Belgian wildcard David Goffin in the first round.

Japan's Kei Nishikori set his sights on emulating his historic run to the Australian Open quarterfinals after the 19th seed marked his return from injury with a 7-5, 6-3, 6-4 victory over Mikhail Kukushkin of Kazakhstan in the first round.