Rafael Nadal sent another ominous warning to his French Open rivals by dropping five games in a third-round win over Italy's Stefano Travaglia.
Nadal, 34, is looking for a record-extending 13th title and looked comfortably at home on Court Philippe Chatrier in a 6-1 6-4 6-0 victory.
Travaglia, 28, won just six points in the first set but settled down to make it more of a contest for the Spaniard.
However, Nadal upped the tempo again to set up a meeting with Sebastian Korda.
"To win against a player like Stefano with this score is because I did a lot of things well, I played more aggressive than the previous days so I'm happy with that," said second seed Nadal.
"I went to the net more often, I hit a lot more winners, my serve is working."
American 20-year-old Korda became the first qualifier in nine years to reach the fourth round by beating Spain's Pedro Martinez.
Son of the 1992 French Open finalist Petr, Korda won 6-4 6-3 6-1 to reach the last 16.
Korda, who is ranked 213th in the world, had not even won a tour-level match in three previous attempts before impressive victories over Italian veteran Andreas Seppi and American 21st seed John Isner at Roland Garros.
Facing 19-time major champion Nadal will be a different prospect.
Korda described Nadal as his "biggest idol" and during his post-match news conference, while Nadal was still playing Travaglia, said he was "praying" for the Spaniard to win.
He even has a cat named after him. "That says a lot about how much I love the guy," laughed Korda.
Korda, who is a former world junior number one, will be hoping not to be overawed by the occasion like Travaglia.
Travaglia, ranked 74th, looked overwhelmed at facing one of the all-time greats and struggled to find his rhythm as Nadal took the opening set in just 23 minutes.
Credit is due, though, for the way he settled down in the second. His service game improved considerably and he held three times before Nadal stamped his authority again with the decisive break in the seventh game of the set.
Questions have been raised about Nadal's title credentials at a place where he has lost just two of 98 matches, based on the cooler conditions in an autumnal Paris and the short preparation on the clay courts because of the coronavirus pandemic.
Sterner tests than Travaglia will come his way. There is a projected meeting with US Open champion Dominic Thiem in the semi-finals and a potential final against top seed Novak Djokovic.
But, by seizing control of the third set, dropping just eight points in it, Nadal sent out a message that he is building towards his best form.
"We are in a very strange situation after a lot of months without playing, especially for me because I did not play in America," said Nadal, who skipped the recent US Open.
"I don't know if that is positive or negative, I take it as a very positive thing because I am playing quite well."