Two-time French Open runner-up Dominic Thiem survived a spirited comeback by a French wild-card entry to win their fourth-round match in five sets.
Thiem, coming off his first Grand Slam title at the US Open, barely got past 239th-ranked Hugo Gaston 6-4, 6-4, 5-7, 3-6, 6-3 at Court Philippe Chatrier on Sunday night.
Thiem called the 3½-hour contest "amazing'' and praised Gaston, saying "his drop shots just are from another planet.''
Added Thiem: "If he continues like this, he's going to be a huge, huge player, and he's going to make a lot of joy in this stadium in the future."
Gaston, 20, was trying to become the lowest-ranked man to reach the quarterfinals in Paris since the ATP computer rankings began in 1973.
Instead, Thiem made it to the quarterfinals at Roland Garros for the fifth time in a row.
Thiem next faces No. 12 seed Diego Schwartzman. He equaled his best Grand Slam showing by reaching his fourth major quarterfinal with a 6-1, 6-3, 6-4 win over Lorenzo Sonego.
The other quarterfinal on that half of the draw will be 12-time champion Rafael Nadal against 19-year-old Jannik Sinner.
Against a player who loves him so much that he named his cat after him, Nadal showed no mercy with Sebastian Korda, seeing off the 20-year-old qualifier with a 6-1, 6-1, 6-2 thumping on Court Philippe Chatrier to reach the quarterfinals at Roland Garros for the 14th time.
Nadal has yet to drop a set in his pursuit of a 13th French Open crown that would give him 20 major titles overall, tying Roger Federer's record.
Korda, the son of 1998 Australian champion Petr Korda, got swept away by Nadal's power on the red clay but did get consoling words of encouragement from his 34-year-old tennis idol, who said the youngster's play was "really impressive."
"All of our generation, we try very hard to be passionate," Nadal said. "If that's a good inspiration for the young generation, that's good."
Nadal's opponent will be dangerous debutant Sinner. By making the men's last eight as a newcomer, the 19-year-old Italian matched a feat last achieved by Nadal himself, in 2005, on his march to the first of his 12 titles in Paris.
So impressive has Sinner been on the clay that his 6-3, 6-3, 4-6, 6-3 win against US Open finalist Alexander Zverev hardly seemed like an upset, despite the 68-spot gulf separating them in tour rankings. Sinner pulled the sixth-seeded German this way and that with precision groundstrokes and unfurled his wingspan to make 21 winners at the net.
Korda's long-term sights are set on winning at least two Grand Slam titles, one more than his dad. In the meantime, the spanking from Nadal was "definitely the best moment of my life.''
"Super awesome," he said. "I asked him for a signed shirt when we were tapping rackets and he said, 'Yeah, no problem.' So I have one in my bag right now. So I'm super stoked.''
Although Nadal and Sinner have practiced together, their match will be the first between the 34-year-old and the youngest man in a Grand Slam quarterfinal since Novak Djokovic in 2006.
"A big challenge,'' Nadal said. "Amazing potential. He moves the hand very quick and he's able to produce amazing shots.''
After his loss, Zverev said that he was unable to compete with full force due to illness.
"I'm completely sick. I can't really breathe, as you can hear by my voice," Zverev told reporters, in a videoconference while wearing a black mask. "I had fever as well. Yeah, I'm not in the best physical state. [Sinner] plays well, but I didn't do anything today. Everything I was doing I was just putting the ball in the court and letting him do everything."
Organizers said the sixth-seeded German player did not consult their doctors before his fourth-round match, despite the symptoms he later disclosed in his news conference.
Organizers said Zverev had stayed up to date with his COVID-19 tests that players have been subjected to every five days. His results were all negative. His most recent test was last Tuesday and he'd been informed Sunday that he was due for another, organizers said.
Sinner said that from his side of the net, his opponent seemed "quite OK, you know, because in the third and fourth set he was running quite a lot.''
Sinner played down any risk of infection.
"We have got tested quite many times,'' he said. "Obviously, we were not that nearby, you know. It's like we always had the distance.''
He added: "I don't think that I will have fever ... or I hope so.''
Organizers say they have conducted about 3,000 tests. They have housed players in two bio-secured Paris hotels. Players wear masks onto the court but not during play, and touch rackets instead of shaking hands.
Information from The Associated Press and ESPN's Pete Bodo was used in this report.