London - Just like that, in a span of 15 days, Rafael Nadal went from French Open champion for a record eighth time to first-round Grand Slam loser for the only time in his career.

Limping occasionally and slower than usual, but unwilling afterward to blame an old left knee injury, the two-time Wimbledon winner exited 7-6 (4), 7-6 (8), 6-4 on Monday against 135th-ranked Steve Darcis of Belgium - one of the most stunning results ever at the All England Club.

"Nobody remembers the losses. People remember the victories," Nadal said, shaking his head as he leaned back in a black leather chair. "And I don't want to remember that loss."

Everyone else definitely will.

It certainly belongs in the same category as his loss a year ago at Wimbledon, in the second round to Lukas Rosol, a player ranked 100th at the time. After that setback, Nadal missed about seven months because of his bad left knee. Since returning, he had gone 43-2 and reached the finals at all nine tournaments he entered, winning seven.

Most recently, in Paris, he collected his 12th Grand Slam trophy, tied for third-most in history, while extending his winning streak to 22 matches.

"Two weeks ago, I was in a fantastic situation, winning a fantastic tournament," Nadal said. "Two weeks later, I lost here in the first round. That's the positive and the negative thing about this sport."

His early defeat rendered moot all the debate in the preceding days about whether Nadal's No. 5 seeding was appropriate or whether Wimbledon officials should have bumped him higher because of past success at the grass-court tournament.

In five appearances at Wimbledon from 2006-11 (he missed the 2009 edition because of knee trouble), Nadal reached the final five times. He won the 2008 and 2010 championships, and was the runner-up to Roger Federer in 2006-07, then to Novak Djokovic in 2011.

Because of Nadal's low-for-him seeding this time - his ranking slid during his time off - he wound up in the same half of the draw as seven-time champion Federer and second-seeded Andy Murray. A possible Nadal-Federer quarterfinal loomed, as did a potential Nadal-Murray semifinal.

So much for that.

"Pretty irrelevant right now," said Murray, who won in three sets Monday, as did Federer. "It's obviously surprising. But, you know, the consistency that Rafa, Roger, Novak have shown in the Slams over the last five, six years, it's going to be almost impossible to keep that up forever."

Two days before Wimbledon started, Nadal spoke about having more trouble on grass than other surfaces lately because its low skids force him to bend his knees so much to reach shots. Nadal decided to skip a grass-court tuneup tournament between the French Open and Wimbledon, opting to rest instead, and arrived in England on Tuesday to begin preparing in earnest.

On Monday, he said, "I didn't move the way I need to if I'm going to win on this surface."

Nadal avoids discussing health issues in the immediate aftermath of a defeat - he didn't reveal the left knee injury last year until weeks after the Rosol match - and Monday was no different. Still, anyone who watched Nadal play Darcis could tell something wasn't right.

Nadal deflected three questions in English about his left knee, saying it's "not the day to talk about these kind of things" and that it would sound like "an excuse." When a reporter asked in Spanish about the knee, Nadal replied: "You're assuming I'm injured." He later did repeat what he mentioned at Roland Garros, which is that the knee is painful at times.

"Maybe he was not in the best shape ever. Maybe he didn't play his best match," Darcis said, noting that he wants to get his hands on of a DVD of the most significant victory of his career. "But I have to be proud."

That's for sure.

Darcis came in 7-18 in Grand Slam matches, a .280 winning percentage, including 12 first-round losses. So when asked his reaction upon hearing last week that he would be facing Nadal, Darcis smiled broadly and gave a one-word answer unfit for publication.

Then he added: "When you see the draw, of course you say, "Ah, it's bad luck."'

While Nadal was struggling, Federer and Murray looked the way title contenders are supposed to in the first round. Federer, the defending champion, needed all of 68 minutes to beat 48th-ranked Victor Hanescu of Romania 6-3, 6-2, 6-0 on Centre Court, as former U.S. Secretary of State Condoleeza Rice looked on from the Royal Box.

In the most noteworthy women's result, fifth-seeded Sara Errani, the 2012 French Open runner-up, lost 6-3, 6-2 to Puerto Rican teenager Monica Puig. Maria Sharapova, the 2004 Wimbledon champion, won in straight sets. So did second-seeded Victoria Azarenka, but not without a scare.

Azarenka twisted her right knee early in the second set, leaving her tumbling to the grass and sobbing. After about a 10-minute break while a trainer wrapped Azarenka's knee, the two-time Australian Open champion finished off a 6-1, 6-2 victory over 106th-ranked Maria Joao Koehler of Portugal.

"I was in such shock," Azarenka said. "You know, for two minutes I had such a consistent pain that it just completely freaked me out."

Reigning U.S. Open champion Murray, trying to become the first British man to win Wimbledon in 77 years, eliminated 92nd-ranked Benjamin Becker of Germany 6-4, 6-3, 6-2.