The top-ranked Nadal broke three times in the first set and once in the second, pinning the Cypriot to the baseline with accurate first serves and precise passing shots.

Nadal advanced to the third round against Juan Martin del Potro, who defeated Marin Cilic 6-3, 6-0.

“I think he’s the worst rival to have to face in the second outing of a tournament,” Nadal said del Potro, the 2009 US Open champion.

Nadal’s match was watched by Real Madrid star Cristiano Ronaldo, who had flown back to the Spanish capital after playing at Barcelona in the Champions League semifinals Tuesday.

“I enjoy watching tennis in Madrid and I support the Spanish players a lot,” Ronaldo said.

Djokovic’s winning streak dates to Serbia’s win in the Davis Cup final last December. He’s 28-0 this year, the best start to a season since Ivan Lendl went 29-0 in 1989.

Djokovic will next play Guillermo Garcia-Lopez of Spain, who has yet to beat the Serb in four meetings.

Djokovic, playing in Madrid for the first time in two years, said the Caja Magica clay courts were very fast, making it hard to control the ball against big servers like Anderson.

The second-ranked Serb was able to break the South African’s serve once in each set.

“It’s a fact that I am playing the best tennis of my life and I’m definitely happy about it,” said Djokovic, who attributed his good form to a “strong mental ability to handle the pressure and play the right shots at the right time.”

Third-seeded Tomas Berdych and fifth-seeded Robin Soderling also won.

On the women’s side, Petra Kvitova of the Czech Republic eased past second-seeded Vera Zvonareva 6-1, 6-4 to reach the quarterfinals.
 

Andre Agassi turned 41 last week, and Pete Sampras will hit 40 this summer, so both were pleased that tennis’ Champions Series is changing to a less-demanding format.

The 2011 schedule, announced Tuesday, shifts from multiple-day tournaments to one-night stops in 12 cities over five weeks. Four of the tour’s seven participants will compete at each event, playing one-set semifinals before the winners meet in an eight-game, pro-set championship match.

“It makes sense for us, because our bodies can sort of withstand the tennis,” Sampras said in a telephone interview. “I can still serve pretty hard, pretty well and sort of paint the lines. That’s what people want to see. I’ll do my best to prepare and go out and not embarrass myself.”

The season begins Sept. 22 at Ft. Lauderdale, Florida, and finishes Oct. 22 at Buffalo, New York, with visits to Washington, Philadelphia, Minneapolis, Boston, Phoenix, Seattle, Los Angeles, Las Vegas, Chicago and St. Louis in between.

In addition to longtime rivals Sampras and Agassi, the players lined up for the tour are Jim Courier, who helped found the Champions Series in 2005 and is now the US Davis Cup captain; John McEnroe, Bjorn Borg, Mats Wilander and Michael Chang.

That group won a combined total of more than 50 Grand Slam singles titles, led by Sampras’ 14. All reached No. 1 in the rankings except Chang, who made it to No. 2.

“We all still can play pretty darn well if we’re healthy and we feel good,” Agassi said on a conference call with Courier, who will be 41 in August. “It’s just the recovery that we all seem to recognize gets tougher as we get older.”

Sampras, Agassi, Courier and Chang came up through the junior ranks together, then dealt with each other throughout their careers on the professional tour.

“It can only help tennis for people to see a generation of American players that might have been the best of all time, especially in cities that haven’t had tennis in a while — Seattle, Philadelphia, Chicago,” Sampras said. “People can get behind it, and maybe some kids might be moved by it, and instead of staying home in front of a computer, they can come see us in person.”

Courier touted the importance of crisscrossing the country to push their sport while, he said, “working hand-in-hand with the local tennis community.”

At season’s end, a bonus pool of $1 million will be split by the top three players in the Champions Series rankings. Tickets go on sale next week.

“It’s a five-week season, which we condensed to make it not only easy to follow for fans and media alike, but also easier for us players to get up from a practice and fitness standpoint and be ready to compete,” Courier said.

Joked Agassi: “Unfortunately, I spent most of my life being older and more experienced than Jim and Pete — and now I just find myself older, so that’s a problem.”

There will be a trainer who will travel to each Champions Series stop, Courier explained, to put “Humpty Dumpty back together again on a nightly basis.”