TURIN, Italy — Top-ranked Jannik Sinner became the first player to advance to the semifinals at the ATP Finals on Thursday. Sinner was assured of a spot in the last four after U.S. Open finalist Taylor Fritz beat Alex de Minaur 5-7, 6-4, 6-3 in their group.

Taylor Fritz benefited from a questionable serving decision by Daniil Medvedev and frustrated his opponent so much that the Russian broke his racket and was docked a point in a 6-4, 6-3 victory for the American in the opening match of the ATP Finals.

TURIN, Italy (AP) — U.S. Open finalist Taylor Fritz benefitted from a questionable serving decision by Daniil Medvedev and frustrated his opponent so much that the Russian broke his racket and was docked a point in a 6-4, 6-3 victory for the American in the opening match of the ATP Finals on Sunday.