Nadal's grass-court streak now stands at 1

Rafa overcomes tough Slovak foe in four sets

Chasing a shot to his right, Rafael Nadal slipped and tumbled to the Centre Court turf.

He popped up, raced across the baseline to get back into the point, and later capped the 14-stroke exchange with a backhand passing winner.

The reason for the two-time Wimbledon champion's recent inability to play well on grass remains something of a mystery. As far as Nadal was concerned on Tuesday, all that mattered was that he dusted himself off and eventually ended a three-match - and seven-set - losing streak on the slick surface.

Overcoming a deficit against a flat-hitting opponent who kept finding lines early, Nadal beat 51st-ranked Martin Klizan of Slovakia 4-6, 6-3, 6-3, 6-3 to reach the second round.

Nadal's reaction afterward - pumping fists, raising arms aloft, tossing souvenirs to the crowd - was rather over-the-top for a guy who owns 14 Grand Slam titles.

"I'm so happy for the victory. In the end, the match was difficult. After the first set, (it) was even more difficult," said the Spaniard, who is ranked No 1 and seeded No 2 but approached this opening-round encounter with some trepidation.

"When you go on court and you lost last year in the first round, the year before in the second round ... (I'm not) going to lie ... it stays in your mind."

Next for Nadal is a match against the man who beat him in 2012's second round, Lukas Rosol of the Czech Republic.

"He is a very dangerous player; very strong, very powerful at the baseline," Nadal said.

Other past champions in action on Day 2 advanced, too, including Roger Federer, Serena Williams and Maria Sharapova, all in straight sets.

Last year, when everything around these parts was turned upside down by surprise after surprise, that trio joined Nadal with early exits; Williams was the last of the group standing, and she departed in the fourth round.

For Nadal, everything comes so easily on red clay, and he just added his record ninth trophy at the French Open. But he said grass is a lot tougher on his knees, which have bothered him for years.

"When I am playing on clay, I don't have to think a lot about what I have to do," Nadal said. "Here, you need to adjust the movement. You need to adjust the rhythm. You need to find the right feeling on the speed of the ball."

Still, Nadal used to be fine on the green stuff.

He played for the title on five consecutive trips to Wimbledon from 2006-11, winning the championship in 2008 and 2010 (he missed the tournament in 2009 because of a knee injury).

But in 2012, he lost to then-100th-ranked Rosol. Last year, Nadal exited in the first round against 135th-ranked Steve Darcis. And this month, Nadal lost his opening match to 65th-ranked Dustin Brown at a grass-court tuneup in Halle, Germany,

For a little more than a set on Tuesday, Nadal ran into trouble again on grass. But this time, he turned things around.

NO INTERNET DATING FOR WOZNIACKI

Caroline Wozniacki appears to be moving on from her breakup with golfer Rory McIlroy. Just don't ask her about Internet dating.

"I think I'm not that desperate," Wozniacki said, smiling. "I'll just see what happens. I'm perfectly fine being single at the moment. It's pretty hard to sweep me off my feet. It would have to take someone very special. You know, you never know."

The 23-year-old Dane was questioned about her love life after beating Shahar Peer of Israel 6-3, 6-0 on Tuesday in the completion of a rain-delayed, first-round match at Wimbledon.

Wozniacki lost her first-round match at last month's French Open just a week after McIlroy ended their relationship as the wedding invitations were being sent out.

Asked again on Tuesday about the breakup, she said: "I feel like I've answered that question a lot of times."

Wozniacki was coy when asked about Feliciano Lopez, a 32-year-old Spanish player.

When a reporter said she seemed to have a "great admirer" in Lopez, she replied: "You noticed?"

The reporter noted Lopez has watched her matches and knows her father.

"He's already making his way in through my dad?" she said with a laugh.

Wozniacki said she noticed Lopez had been "on the sidelines" of her matches at last week's Wimbledon warm-up in Eastbourne, where the Spaniard won the men's title.

"He's a great guy," she said. "This is very awkward."

Wozniacki also spoke of her bond with Serena Williams, calling her "an amazing friend." The two spent time together in Miami after their early exits in Paris, where Williams lost in the second round.

"She's always been there for me whenever I've needed her," Wozniacki said.

"After everything that she's achieved in her professional career, as well, that she finds time ... she wants to help out a friend who needs it sometimes. It's just nice to have good people around you."

Rafael Nadal celebrates beating Martin Klizan during their first-round match on day two of Wimbledon on Tuesday. Nadal won 4-6, 6-3, 6-3, 6-3. Carl Court / Agence France-presse