World number-one Roger Federer and Spanish stud Rafael Nadal took the first step towards their much anticipated semi-final meeting with relative ease Monday.

　　Federer's only hiccup against Israel's Dudi Sela on Court Philippe Chatrier came early in the second set when he fell behind 1-3, but the Swiss reeled off 11 of the next 12 games to run away with a 6-1 6-4 6-0 decision.

　　"It was alright," Federer said of his performance. "Just happy to be through, really. There's good moments, but also, you know, bad moments.

　　Although he made an uncharacteristic 17 unforced errors in the opening set, Federer displayed his usual supreme shot-making ability, especially at the net (winning 75 percent of net points played) and in that dominating third set.

　　"Once I win a set 6-1, I'm not going to lose a match," Federer said.

　　This is Federer's seventh consecutive clay court victory since his loss to Richard Gasquet in Monte Carlo.

　　Nadal, meanwhile on Court 1 in his Roland Garros debut, had to work a bit harder to advance past Lars Burgsmuller of Germany 6-1 7-6 6-1.

　　"I don't play my best match today," said Nadal, who is still trying to learn English. "I going to practice tomorrow and I will try to improve my tennis."

　　Nadal was sharp in the first set, but found himself down 1-3 in the second set tiebreaker. The lefty won the next four points, though, and had little trouble closing out the set and then the match.

　　"I want to play my best tennis here," Nadal said, "but it is not easy. I can't play well every match. I need to improve a lot of my tennis for next days."

　　Nadal's tour-best winning streak is now 18 matches. He moves on to face Xavier Malisse, who embarrassed American Mardy Fish 6-2 6-1 6-1 in an hour and 13 minutes. Federer will next play Spain's Nicolas Almagro.