“Of course you are under stress when you see that you have opportunities almost in every game, and you are not able to convert it,” Nadal said. “Yeah, of course, when finally I did it, everything changed. I was able to play more free, to start to attack better with my forehand.”
He added that he hoped the last three sets could be a turning point for him.
“You need matches like this,” Nadal said. “Then now I have the opportunity to compete again, to try to do it well, no? I am in the second week. That’s the important thing.”
Federer similarly righted a listing ship Saturday to maintain his course, which could include a semifinal against Nadal. After five-set slogs against Frances Tiafoe and Mikhail Youzhny in the first two rounds, third-seeded Federer found his rhythm with a 6-3, 6-3, 7-5 victory over 31st-seeded Feliciano López.
“Usually I play very well, but I struggled the first couple rounds,” Federer said. “I played a very clean match. I couldn’t be happier.”
Federer’s backhand was especially improved. After a winners-unforced errors differential of minus-49 over his first two matches, he was even in that category on Saturday.
Federer improved to 13-0 in his career against López. Federer is 11-0 against his fourth-round opponent, 33rd-seeded Philipp Kohlschreiber, who defeated 235th-ranked John Millman, 7-5, 6-2, 6-4.
Nadal next faces Alexandr Dolgopolov, a Ukrainian who dominated Viktor Troicki, 6-1, 6-0, 6-4, in just 1 hour 22 minutes.
Dolgopolov, an unorthodox player with jerky strokes, has made more headlines at this tournament for a loss last month in Winston-Salem, N.C., which was found to have unusual betting patterns. His postmatch news conference was held in the tournament’s main interview room for the first time Saturday, and Dolgopolov grew agitated when he was repeatedly asked questions similar to the ones he had faced after his first match here.
“I’m here not to talk about betting,” Dolgopolov said. “I already said everything that could be said, and you guys want to give me again the same questions or what?”
Ninth-seeded David Goffin, the highest-ranked player Nadal could face before the semifinals, won, 7-5, 5-1, when 18th-seeded Gaël Monfils retired because of a right knee injury.
Monfils, a semifinalist at the Open last year, had been the only one of last year’s four semifinalists to play a match at this year’s tournament.
“I started to see at the beginning of the second set that he was struggling with his knee,” Goffin said. “And, yeah, after three or four games, it was almost the end.
“But you never know with Gaël,” he added with a smile.
Goffin next plays 53rd-ranked Andrey Rublev of Russia, who beat 56th-ranked Damir Dzumhur, 6-4, 6-4, 5-7, 6-4. Rublev, 19, is one of two teenagers to reach the second week of the tournament on the men’s side, joining the Canadian qualifier Denis Shapovalov, 18.
Juan Martín del Potro, a champion here in 2009, won, 6-3, 6-3, 6-4, over 11th-seeded Roberto Bautista Agut. Like Nadal and Federer, del Potro said he thought he played his best match of the tournament in this round.
“I came to the net very often, tried to be aggressive all the time, and I think I play well,” said del Potro, the No. 24 seed.
In the fourth round, del Potro will face sixth-seeded Dominic Thiem, who beat 30th-seeded Adrian Mannarino, 7-5, 6-3, 6-4. Del Potro and Thiem also played in the fourth round here last year, but Thiem was forced to stop the match midway through the second set because of a right knee injury.