Frances Tiafoe hadn’t dropped a set on the way to the French Open quarterfinals, but he wasn’t up to the task against Lorenzo Musetti.

Lorenzo Musetti advanced to his first semifinals appearance at the French Open Tuesday with a four-set win over Frances Tiafoe. Musetti held off Tiafoe despite receiving an unsportsmanlike conduct warning in the second set after inadvertently hitting a line judge with a ball he kicked toward the back wall at Roland-Garros out of frustration.

Frances Tiafoe has defeated Daniel Altmaier 6-3, 6-4, 7-6 (4) to reach the French Open quarterfinals for the first time.