Nadal wins in front of Queen Sofia in Madrid

MADRID (AP) " Rafael Nadal powered into the third round of the Madrid Open on Wednesday with a convincing 6-3, 6-1 win over Jurgen Melzer.

The top-ranked player made just three unforced errors playing on clay in front of Spain's Queen Sofia, and converted all four of his break points.

"It's more difficult to play here than on normal altitude surfaces," Nadal said of playing 1,970 feet above sea level. "You can do more with the ball with less effort, but your opponent also does it."

The only break in Nadal's concentration came when a ball girl fainted and had to be carried off the center court for medical assistance in the second set.

Earlier, Novak Djokovic beat Oscar Hernandez 6-3, 6-3. The third-seeded Serb fell awkwardly on his right knee on the clay surface at Madrid's new "Magic Box" tennis center in the second set, but was rarely troubled by his opponent.

"I was aware the court was quite wet because I saw they had watered it after the previous match. But I was lucky that I fell in a good way so there is no injury," Djokovic said. "It looked easy, but it wasn't. I played just well enough to win."

Djokovic never faced a break point in the match, while breaking Hernandez once in the first set and twice in the second.

Djokovic recently fell from third to fourth in the rankings, surpassed by Andy Murray despite winning the Serbia Open last week " the country's first ATP Tour event that he also helped organize.

"I try not to pay too much attention to rankings," he said. "But I am motivated to win back my third ranking position."

Nadal agreed with Djokovic that the way the rankings are calculated, players are forced to play too many tournaments.

"The way things are now, you can't choose which events you would like to focus on, you have to play everything in order to defend your position," Nadal said. "But it's the same for everyone."

Nadal's next opponent is Phillipp Kohlschreiber, who beat 13th-seeded Marin Cilic 6-1, 6-7 (5), 7-6 (2).

"He hits the ball very hard and cleanly, so I'd like to make sure my serves are winners against him," Nadal said.

Sixth-seeded Andy Roddick squeezed past Tommy Haas 1-6, 7-6 (9), 6-4, eighth-seeded Gilles Simon beat qualifier Fabio Fognini 6-3, 6-2 and other winners included Nikolay Davydenko, Stanislas Wawrinka and James Blake, who withstood 26 aces from Ivo Karlovic to set up a match with Roger Federer after a 6-7 (4), 6-4, 7-6 (4) win.

Juan Martin del Potro of Argentina also advanced when Tomas Berdych was forced to retire with a leg injury. The Czech player, who won his first title of the year at the BMW Open in Munich on Sunday, retired while trailing 6-2, 4-1.

In the women's event, top-ranked Dinara Safina beat Li Na 6-3, 7-6 (2), Amelie Mauresmo defeated third-seeded Elena Demetieva 1-6, 6-4, 6-2. Victoria Azarenka eased past Peng Shuai 6-4, 6-1, and Vera Dushevina stopped Francesca Schiavone 6-3, 4-6, 6-2.