New York, September 7 :

Rafael Nadal was upset in the US Open quarter-finals by 54th-ranked Mikhail Youzhny of Russia 6-3, 5-7, 7-6 (5), 6-1 on Wednesday, thwarting an anticipated third-straight meeting against Roger Federer in the final of a Grand Slam.

“Unbelievable,” Youzhny said. “I cannot believe I beat Rafa in four sets.” Youzhny never before had been beyond the fourth round of a major tournament. Youzhny displayed the sort of aggressive and on-the-mark shotmaking he used to knock off No 6 Tommy Robredo, No 11 David Ferrer and No 19 Dominik Hrbaty earlier in the tournament.

Before Wednesday, he was 0-6 against players at No 1 or 2. But his high-risk style worked to perfection against Nadal. Youzhny compiled more than twice as many winners as Nadal (49-23), limiting Nadal to one in the fourth set.

On the other side of the men’s draw, the top-seeded Federer moved into a quarter-final against No 5 James Blake, both winning in straight sets. That half’s other quarter-final will be No. 7 Nikolay Davydenko against No. 14 Tommy Haas. There still could be a No 1 vs No. 2 final for the women, because top-seeded Amelie Mauresmo and Justine Henin-Hardenne advanced with relative ease. Coming off a three-set struggle against Serena Williams, Mauresmo beat No 12 Dinara Safina 6-2, 6-3 to move a step closer to her third Grand Slam title of the year. Mauresmo next faces No 3 Maria Sharapova, a 7-6 (7/4), 7-6 (7-0) winner over No 27 Tatiana Golovin.

Henin-Hardenne defeated Lindsay Davenport 6-4, 6-4 in a showdown between former champions to set up a semi-final against No 19 Jelena Jankovic.

Henin-Hardenne needed a massage after the first set for a twinge in her back and sore rib, then dropped the first five points of the second set and wound up trailing 3-1. But the Belgian broke right back, and again to go ahead 5-4.

Like Mauresmo, Federer is aiming for major title No 3 of 2006, but he’s aiming for No 9 of his career. The two-time defending champion won the first 12 points en route to a 6-3, 7-6 (2), 6-3 victory over Marc Gicquel. Blake, meanwhile, saved all 15 break points he faced and eliminated No 12 Tomas Bedrdych 6-4, 6-3, 6-1.