Nadal hasn't lost a match on clay in more than two years and that includes sweeping through the Monte Carlo Masters tournament last year. On Thursday he dispatched Kristof Vliegen 6-1, 6-1 in 65 minutes. At one point Nadal won 21 consecutive points.
Federer next goes against 12th-seeded David Ferrer, who upset No. 6 Novak Djokovic 7-5, 6-4 on Thursday while Nadal faces qualifier Philipp Kohlschreiber, who outlasted Guillermo Garcia-Lopez in a grueling 5-7, 7-6 (7-4), 7-6 (7-4) match.
Also Thursday, 10th-seeded Tomas Berdych was a 1-6-, 6-3, 6-2 winner over fifth-seeded Tommy Robredo; No. 11 Richard Gasquet upset seventh-seeded Ivan Ljubicic 6-3, 6-7 (5-7), 7-5; Juan Carlos Ferrero dumped Igor Andreev 6-3, 6-3; and Robin Soderling topped Max Mirnyi 7-6 (7-5), 6-2.
In addition to the Federer-Ferrer and Nadal-Kohlschreiber quarterfinals on Friday Berdych is to play Soderling and Gasquet is to meet Ferrero.