Carlos Alcaraz produced an incredible moment of sportsmanship during his French Open fourth-round showdown with Ben Shelton on Sunday. The Spaniard scraped through the first set and was at a crucial moment in the opening game of the second when he insisted on being honest, even at his own expense.

Shelton had Alcaraz scrambling with a cross-court forehand, and the crowd were wowed when the second seed somehow managed to get it back over the net. But almost immediately, Alcaraz came clean to the chair umpire and admitted that he was only able to make contact with the ball by throwing his racket.

Rules state that a point is only valid if a player is in control of their racket when hitting the shot. And although Alcaraz's effort was remarkable, he acknowledged that it was also illegal and informed the umpire knowing that Shelton would not only be given the point, but also work his way up to break point as a result.

Alcaraz was widely praised for his sportsmanlike conduct, and in the end his concession counted for little as he strolled the second set 6-3. The 22-year-old is the defending champion at Roland-Garros, but in 13th seed Shelton he was handed a daunting draw against a powerful player.

And Alcaraz's task was made even more difficult by his late-night win over Damir Dzumhur on Friday, which prompted his team to cancel their Saturday practice sessions and rest up for the Shelton clash.

"He’s a very aggressive player," said Alcaraz. "He puts a lot of energy into his shots and into his matches. When we’ve crossed paths we’ve played good tennis. He’s getting better and better on clay."

Alcaraz required four sets against Dzumhur in the third round and Fabian Marozsan in the second en route to his meeting with Shelton. The American went five sets with Lorenzo Sonego in round one, went straight through due to a walkover in round two, and thrashed Matteo Gigante in round three to secure his deepest Roland-Garros run to date.

Elsewhere in the men's draw, Tommy Paul advanced to the quarter-finals with a straight-sets win over Alexei Popyrin on Sunday, while Frances Tiafoe came up against the unseeded Daniel Altmaier. A tasty clash between Lorenzo Musetti and Holger Rune is pencilled in for the last match of the day on Court Philippe-Chatrier.