MADRID, Spain -- Andy Roddick's 20-match winning streak ended with a stunning 7-6 (3), 6-2 loss to unseeded Nicolas Massu in the third round of the Tennis Masters Series in Madrid on Thursday.

Roddick, the U.S. Open champion, let the first set slip away after leading 5-2, then had his powerful serve broken twice in the second set. He ended the match by double-faulting.

"The one thing I didn't do that well today was the serve," Roddick said. "Besides that, I played OK. He returned well."

It was the American's first loss since Tim Henman beat him in the semifinals at Washington, D.C., in August.

"Clearly, this was one of the best matches in my life," said Massu, a Chilean ranked 21st in the world -- 19 spots below Roddick.

After one backhand passing shot down the line by Massu, Roddick applauded with his racket.

"He played a great match," Roddick said. "A couple of points I thought I had him, and he came up with shots that were too good."

In the tiebreaker, Roddick's ace gave him a 3-2 edge, before Massu won five straight points.

Massu broke Roddick to lead 2-0 in the second set, then won his own next two service games at love.

World No. 1 Juan Carlos Ferrero edged fellow Spaniard Felix Mantilla 7-6 (2), 7-6 (0) in the last match of the night. It ended well past midnight with several thousands fans still in the Rockodrome Arena.

Earlier, Wimbledon champion Roger Federer, Sebastien Grosjean, Paradorn Srichaphan and Younes El Aynaoui eliminated American opponents in straight sets to reach the quarterfinals.

The third-seeded Federer beat Mardy Fish 6-3, 7-6 (4), No. 6 Grosjean defeated Vince Spadea 6-3, 6-2, No. 7 Paradorn got past Jan-Michael Gambill 7-5, 6-4, and No. 15 El Aynaoui topped Robby Ginepri 6-4, 7-6 (5).