Lorenzo Musetti has been warned for unsportsmanlike conduct for kicking a tennis ball that inadvertently hit a linesperson during his French Open quarterfinal against Frances Tiafoe.

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.

No. 8 Lorenzo Musetti defeated No. 15 Frances Tiafoe 6-2, 4-6, 7-5, 6-2 in the French Open quarterfinals on Tuesday at Roland-Garros.