A worn-out Rafael Nadal winced and dropped to the court, sitting with legs stretched out and head bowed.

The no. 2-seeded Spaniard was moments away from a fourth-round loss at the U.S. Open to no. 15 David Ferrer, but far more surprising than the result was the mere sight of the indefatigable, irrepressible Nadal, down and out.

Nadal is a three-time French Open champion and a two-time Wimbledon finalist, but he has yet to solve the hard courts of Flushing Meadows, and Ferrer ran him ragged, winning 6-7 (3), 6-4, 7-6 (4), 6-2 in a match that ended at 1:50 a.m. today.

“I prefer not to speak about my body right now,” Nadal said afterward, saying he thought it would sound as if he were making excuses. “He played very good and he beat me.”

So much for a third consecutive Grand Slam final between Nadal and no. 1 Roger Federer.

“Sure there is disappointment for me, but that is tennis,” Nadal said.

He wound up on the ground after failing to handle an on-the-run shot in the next-to-last game. Earlier in the fourth set, Nadal grimaced between points and sometimes reached down to grab his foot, as though it might have been cramping.

After missing a shot late in the third set, the left-hander flexed his racket hand repeatedly. Then, with Ferrer serving at 1-1, 40-30 in the fourth, Nadal called for a trainer and had him put some ice on that left finger.

Nadal injured his left knee during a practice session the day before the tournament began and considered withdrawing. He struggled through the first round, then looked much fitter in his next two matches.

He wore thick strips of white tape below both knees against Ferrer, but that didn’t appear to be an issue this time.

Ferrer, however, was.

He leads the ATP in most returning statistics and on this night he broke Nadal seven times, including to go up 4-2 in the fourth set. He also matched Nadal’s court coverage and big groundstrokes throughout, often ending points with a flick of his wrist and a loud grunt.

“To beat Rafa, I have to run a lot. Tonight is very special,” Ferrer said.

The victory put Ferrer in his first U.S. Open quarterfinal, where he will meet no. 20 Juan Ignacio Chela. The other quarterfinal matches are no. 1 Federer vs. no. 5 Andy Roddick, no. 3 Novak Djokovic vs. no. 17 Carlos Moya and no. 4 Nikolay Davydenko vs. no. 10 Tommy Haas.

Nadal beat Federer in the past two French Open finals and lost to him in the past two Wimbledon finals but never has been past the quarterfinals at the U.S. Open.

The 25-year-old Ferrer, meanwhile, is headed to only the second Grand Slam quarterfinal of his career. The other came at the 2005 French Open, where he lost to – guess who? – eventual champion Nadal.

Nadal entered yesterday having won four straight against his fellow Spaniard, but as the favorite said afterward about Ferrer: “He’s a very good player. He’s having an unbelievable season.”

Early on, Ferrer was unsettled by the overhead video screens in Arthur Ashe Stadium, which sometimes show live shots during play. He complained a couple of times to the chair umpire, who had tournament referee Brian Earley come out to discuss it.

“It’s unbelievable,” Ferrer told Earley. “It’s impossible to focus.”

Earley explained to the player the screens would stay on.

“He said it was distracting him. This is his first time playing on this court, so you can understand it,” Earley said. “But we’re not turning it off.”

Once Ferrer got used to the setting, he sparkled.