Rafael Nadal and Dominic Thiem continued their smooth progress through the draw at Roland Garros but the day belonged to 20-year-old Frenchman Hugo Gaston.

The wild card, ranked 239th, began the tournament without a tour-level win but is through to the fourth round after a 2-6 6-3 6-3 4-6 6-0 victory over former champion Stan Wawrinka.

Wawrinka had been tipped as a potential title challenger in the slow, heavy conditions but he was simply unable to hit through the brilliant defence of Gaston, who looked stunned by his own achievement.

The £170,000 in prize money that the Frenchman has secured by reaching the fourth round is more than he has earned in the rest of his career put together.

Gaston said: “It’s difficult to explain. It’s fantastic. It was a great match. I’m very happy today. Before I was always watching this on TV. Today I can play on these courts, so it’s amazing for me.”

Gaston is the lowest-ranked man to reach the fourth round at Roland Garros for 18 years but not the only player outside the top 200.

Sebastian Korda, also 20, is through too after a 6-4 6-3 6-1 victory over fellow qualifier Pedro Martinez.

Korda is the son of former grand slam champion Petr Korda and his reward is a clash with his childhood idol Nadal.

“He’s one of the reasons I play tennis,” said Korda. “Just watching him play, unbelievable competitor. Just from him I have the never-give-up mentality. Whenever I’m on court, I try to be like him.

“Growing up, I named my cat Rafa after him. That says a lot about how much I love the guy.”

When informed of the other Rafa, Nadal, who breezed past Stefano Travaglia 6-1 6-4 6-0, said with a smile: “That means that I have been on the TV for such a long time, that’s the main thing. Another negative thing that means is that I am 34.

“But I’m happy to hear that. I know he’s playing great. He’s a very young kid with a lot of power. I think he has an amazing future – hopefully not yet.”

Gaston will take on third seed Thiem, who rated his victory over Casper Ruud as one of his best performances of the season.

The US Open champion has yet to drop a set at Roland Garros and recovered from a slow start to beat in-form Norwegian Ruud 6-4 6-3 6-1.

The Austrian said: “I think that he was playing well from beginning to the end basically. I really raised my level. Maybe the first four games were not as good as the rest of the match by me, but he’s a really good player, especially on clay, probably one of the best of the season.

“In general I was super-happy with my performance. I think it was one of the best ones this year.”

Ruud, 21, has won more clay-court matches than any other player in 2020 and he was unfortunate to run into Thiem so early in the tournament.

Ruud was also unfortunate on a couple of line calls, particularly one early in the second set when he was adamant a Thiem shot missed the baseline only for the umpire to decide it was in.

The calls are growing for technology to be used to review line calls on clay, as on other surfaces, with Denis Shapovalov also the victim of an apparent umpiring mistake at a crucial moment during his loss to Roberto Carballes Baena on Thursday.

Clay-court events have generally persisted with umpires checking the mark on the clay for contentious calls, with Hawk-Eye not yet deemed to be accurate enough.

Ruud said: “I think definitely that we should start using Hawk-Eye for the clay-court tournaments as well because then we don’t need to have all these arguments with umpires. And I think, quite frankly, we players are right on these mark discussions.”

Italy are a growing powerhouse in the men’s game and they have two men through to the fourth round – Lorenzo Sonego and exciting 19-year-old Jannik Sinner.

Sinner next faces sixth seed Alexander Zverev, who for once took the straightforward route to a 6-1 7-5 6-3 win over Marco Cecchinato, while in-form Diego Schwartzman beat Norbert Gombos 7-6 (3) 6-3 6-3.