There was calm in 22-year-old Lucas Pouille’s eye, like a hurricane, and ultimately no shelter for Rafael Nadal from their fourth-round U.S. Open match that developed into a five-set tempest.

Nadal, the 14-time major-tournament champ, had been steadily gathering force in rallying from a two-sets-to-one deficit. But the composed Pouille, who first broke into the world’s top 25 only two months ago, refused to take the hint.

Time and again through the deciding final set, Pouille answered Nadal’s sustained pressure with his own damaging blows. Backhands down the line. Aces. Inside-out forehands to the open court. Volleys and delicate drop shots.

Until finally, 14 points into the fifth-set tiebreaker, Pouille’s ripped forehand caught the sideline to lock up a 6-1, 2-6, 6-4, 3-6, 7-6 (6) upset.

For the 30-year-old Nadal, who won the Open in 2008 and 2010 but missed 2012 and 2014 with injuries, it was his fifth consecutive early exit from a Slam. (A wrist problem forced him to withdraw after the third round in this year’s French Open and he then skipped Wimbledon.)

Pouille, meanwhile, may be younger and fresher but is new to this level of success. In his first 11 Slam appearances, he never got past the second round until this year’s Wimbledon, when he reached the quarterfinals. He is far less accustomed to the kind storm the two men involved themselves in Sunday.

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But that wasn’t the point, Nadal said. “Experience, when you are 4-3 in the third and 30-love, it’s not a question of experience, no?” Nadal said of surrendering Pouille’s fifth and final service break. “It’s a question of playing a little bit better than what I did. Needed to play with a bit more calm. He played well. That’s it.”

Their wrangle took four hours and seven minutes, and it was the third consecutive five-set Open match for the tireless Pouille. (He needed a mere four sets in his first-round victory.)

He said it took “everything” to hold off Nadal. The 11 aces he struck compared to Nadal’s one. A startling 87-percent success rate in returning Nadal’s serves.

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With Pouille serving at 4-4 in the fifth, he had to save one break point and go to deuce three times before he cornered Nadal into netting a forehand to hold serve. Nadal needed only five points in the next service game to pull back to 5-5.

A defensive volley at game point put Pouille back ahead at 6-5, then Pouille sent a return long and they again were even at 6-6.

“I was like, ‘OK, I’m going to win this one,’ ” Pouille said. “When it was 6-6, not the same. It’s never over until the last points. I came back. He came back.”

A Pouille volley, Pouille backhand, Pouille ace and Nadal error and Pouille jumped to a 4-1 lead in the tiebreaker, and it was 6-3 when Nadal crept back by saving three match points.

That was the former champ’s last rush, though. “I couldn’t,” Pouille said, “dream better than this.”