Jannik Sinner opened his ATP Finals title defence in ruthless fashion, dispatching an injured Felix Auger-Aliassime 7-5, 6-1 before an electric home crowd in Turin.
The Italian second seed was dominant on serve throughout, winning 24 of 27 first-serve points and never facing a break point.
Auger-Aliassime battled gamely in a tight first set but appeared to tweak his left calf late on, calling for the physiotherapist twice in the second set and managing just one game.
Victory placed Sinner top of the Bjorn Borg Group as he chases both a successful title defence and the year-end world No.1 ranking.
He must retain his crown and hope Carlos Alcaraz drops a group match and misses the final to finish the season at the summit.
Sinner has now won 27 consecutive matches on indoor hard courts and remains unbeaten against top-10 opponents other than Alcaraz since August 2024.
Earlier in the day, Taylor Fritz powered past Lorenzo Musetti 6-3, 6-4 in the Jimmy Connors Group.
