For the first time in his career, Rafael Nadal lost a Grand Slam match after taking a two-set lead.
And for the first time since 2004, he will end a season without winning at least one Grand Slam title.
"The only thing it means," Nadal said about that streak coming to a close, "is I played amazing the last 10 years."
Once so seemingly invincible, able to run down every last ball and tough to slow down once out in front, Nadal was beaten 3-6, 4-6, 6-4, 6-3, 6-4 by 32nd-seeded Fabio Fognini of Italy in the third round of the U.S. Open.
"To win like that -- against him, from two sets down -- is something incredible," Fognini said, calling it a "mental victory."
The eighth-seeded Nadal's defeat, which finished at nearly 1:30 a.m. on Saturday, follows exits in the quarterfinals at the Australian Open and the French Open, then the second round at Wimbledon.
He said he must "accept that (it) was not my year."
Once ranked No. 1, he dropped as low as No. 10 in 2015, his lowest spot in a decade. The 29-year-old Spaniard also has spoken openly about a crisis of confidence.
"What I (am) doing worse is playing worse than what I used to do the last couple of years," he said. "That's it."
Nadal, who has won two of his 14 career major titles at Flushing Meadows, not only claimed the first two sets against Fognini, but also led by a break in the third at 3-1.
He couldn't sustain it, though, as Fognini began taking more high-risk shots -- and putting plenty right where he wanted them, winding up with more than twice as many winners as Nadal, 70 to 30.
"You have to attack him," Fognini said.
Asked how it was possible that an opponent could produce that many winners against him, Nadal smiled and joked: "Maybe I am slower."
Ripping big groundstrokes off both wings, many on a full sprint, for more than 3 1/2 hours, the two men engaged in entertaining exchanges that thrilled the Arthur Ashe Stadium crowd that included Tiger Woods.
"An incredible match, for sure," Fognini said. "We killed ourselves."
The 52-minute fifth set alone was filled with one apparent momentum swing after another. Starting at 1-all, there were seven consecutive breaks of serve, a pattern that finally ended when Fognini broke to go ahead 5-4, then held to end it.
Fognini reached the fourth round at Flushing Meadows for the first time. The last Italian man to get that far at the U.S. Open was Davide Sanguinetti a decade ago.
Nadal, meanwhile, had won 22 of his last 23 U.S. Open matches, including earning championships in 2010 and 2013, and reaching the final in 2011. He missed the tournament because of health issues in 2012 and last year.
He tried to look on the bright side as he spoke to the media at about 2:30 a.m., saying that he was pleased that his mind allowed him to "fight until the end, something that I was missing for a while."
But Nadal acknowledged there are problems with his strokes, particularly not enough topspin on his forehand and too-shallow groundstrokes in general.
"Easy to understand, easy to explain, difficult to change," Nadal said. "But I'm going to do it."
Follow Howard Fendrich on Twitter at http://twitter.com/HowardFendrich