Sinner had a straight set victory over Ben Shelton.
Jannik Sinner has maintained his winning run at the ATP Finals tennis with a straight sets victory over Ben Shelton.
The Italian defending champion is already through to the knockout stages of the season-ending tournament in Turin.
It's winner takes all tonight when Alexander Zverev faces Felix Auger Aliassime for a place in the semi-finals.

Wales Stun All Blacks To End 73-Year Wait For Victory
Ireland Face Must-Win Kosovo Clash After Narrow Defeat To Austria
Kildare Trio Feature As Ireland Overcome Fiji In Nations Championship
Kildare's Sean O'Haire Kicks Dramatic Last-Minute Winner In American College Football
Sunday Morning Sports Update
Milltown Through To Leinster Intermediate Semi-Finals After Victory Over Meath Champions
Sarsfields Leinster Championship Campaign Ends After Heavy Defeat To Cuala
More Than 20 Horses Withdrawn At Cheltenham Over Ground Conditions