Reigning champion Carlos Alcaraz won a war of attrition with American 13th seed Ben Shelton to reach the French Open quarterfinals on Sunday.

The Spaniard emerged victorious 7-6 (10/8), 6-3, 4-6, 6-4 after over three hours of blistering serves, power-hitting and drop-shots on Court Philippe Chatrier.

READ: Carlos Alcaraz wobbles but reaches 2025 French Open last 16

“I think we both have huge respect to each other, we entertained the people well,” Alcaraz said on court.

“He’s a really powerful player — he can make any shot… I appreciate the moment that I’ve shared with him today.”

The four-time Grand Slam winner edged a tight first set, which produced only one unconverted break point, at the end of a lengthy tie-break that saw both players have chances to clinch the opener.

When Alcaraz finally forced a break against the big-serving Shelton in the second set, it was enough for him to move into a two-set lead.

But once again Alcaraz failed to see out a straight-sets victory as Shelton produced two breaks of serve to edge the most open of the four frames.

READ: Carlos Alcaraz survives to keep French Open defense on track

The 22-year-old nonetheless bounced back to gain the advantage in the fourth set, before serving out as dusk descended over centre court.

Another American awaits Alcaraz in the last eight after 12th seed Tommy Paul earlier defeated Alexei Popyrin in straight sets.

“I remember that every match that I’ve played against him he was really tough. He was really difficult,” said Alcaraz of Paul.

“In Grand Slams, in Masters 1000, and all the tournaments I’ve played against him it wasn’t easy at all. I lost a lot, a few matches against him as well. He is in the quarter-finals of another Grand Slam, so his level is really high right now.”

Alcaraz leads his series with Paul 4-2, and most recently defeated the 28-year-old in straight sets on the red dirt of Roland Garros at the quarter-final stage of the 2024 Olympic Games.