PARIS — Lorenzo Musetti used his sleek one-handed backhand and sprint-then-slide court coverage to reach his first semifinal at the French Open, and second at a Grand Slam tournament, by beating Frances Tiafoe 6-2, 4-6, 7-5, 6-2 Tuesday in the same stadium where he won a bronze medal at last year’s Olympics.

The eighth-seeded Musetti, a 23-year-old Italian, improved to 19-3 this season on red clay. When the match ended, he rolled up the right sleeve of his green shirt and flexed his biceps.

He’ll face defending champion Carlos Alcaraz or American Tommy Paul on Friday for a berth in the championship match.

Musetti and No. 1 Jannik Sinner — who faces unseeded Alexander Bublik in the quarterfinals Wednesday — gave Italy two male quarterfinalists at Roland-Garros for the first time since 1973.

Tiafoe also was part of a rare duo: He and Paul were the first American men to get to the round of eight in Paris since Andre Agassi in 2003 — and the first duo to do it in the same year since Jim Courier and Pete Sampras in 1996.

And the 15th-seeded Tiafoe, a 27-year-old from Maryland, made it all the way to the quarterfinals without dropping a single set. But he was not quite up to the task against Musetti, who was a semifinalist at Wimbledon in 2024, and it showed right away.

Wearing a chain around his neck with a pendant reading “Big Foe” in capital letters, Tiafoe missed all eight first serves in his initial service game and sent a backhand wide to give Musetti a break and a 2-0 lead. He looked up at his coach, David Witt — who’s worked with Venus Williams and Jessica Pegula in the past — and complained about the wind.

The deficit was 3-0 after 13 minutes. By the time that set was over, 21 of Musetti’s 30 points had arrived via mistakes by Tiafoe, nine forced and 12 unforced.

Two-time U.S. Open semifinalist Tiafoe’s first break delivered a 2-1 lead in the second, and when he smacked a forehand winner to even the match at a set apiece, he let out a roar and shouted, “Let’s go! Let’s go!”

During that set, Musetti was warned for unsportsmanlike conduct for kicking a tennis ball that inadvertently hit a linesperson. Unlike most top-level tennis tournaments, which rely on electronic line-calling, there are still humans on court at Roland-Garros to decide whether shots land in or out.

The point of the match came in the third set’s sixth game.

Musetti stretched wide of the doubles alley near the net to reach a shot at a seemingly impossible angle. Tiafoe then did the same in response, sending his near the baseline. Musetti ran and, with his back to the net, twisted his body to somehow flick a low ball back with a half-swing. It worked, though, and Tiafoe — perhaps startled to see the point wasn’t over — netted an awkward, shoulder-high volley.

That set swung Musetti’s way when he broke in its last game. On a 12-stroke exchange, Tiafoe tried an ill-advised and ill-struck drop shot that the speedy Musetti got to, conjuring up a down-the-line backhand winner. Now it was his turn to celebrate, punching the air and yelling.

Musetti broke again to lead 2-0 in the fourth, and soon it was over.

He is now 13-4 in his French Open career, and three of those losses came against an opponent ranked No. 1 — Novak Djokovic twice, Alcaraz once. The only way he’ll need to deal with the top-ranked man again in Paris is if it’s his pal Sinner standing across the net on Sunday with the trophy in the offing.