Spain's Carlos Alcaraz got back on track at the ATP Finals with a 7-5 6-2 win over Andrey Rublev to revive his hopes in Red Group.
World number two Alcaraz suffered an opening round-robin defeat by Alexander Zverev, but responded with a confident display, albeit against an unravelling Russian.
Rublev managed to hang on in the first set but wavered at 5-5 when he dropped his serve -- Alcaraz then claiming the opening set with a comfortable hold.
Things deteriorated rapidly for Rublev when he dropped serve at the start of the second set. He slammed down his racket after handing Alcaraz a break point and when he then blazed a shot wide, he repeatedly smashed his racket into his leg.
The Turin crowd gasped and an emotional Rublev had to wipe blood off his knee during the changeover.
Alcaraz took complete control after that with Rublev seemingly playing against the Spaniard and himself. The contest reached its predictable conclusion in little more than an hour.
Elsewhere, India's Rohan Bopanna made history at the ATP Finals when he became the oldest player ever, 43, to win a match at the year-ender after teaming up with Matthew Ebden to beat Rinky Hijikata and Jason Kubler 6-4 6-4 in a round-robin match.
Bopanna and his Australian partner are now 1-1 in their group and could still qualify for the semi-finals depending on the result of their match against Wesley Koolhof and Neal Skupski on Friday.
The previous oldest player to win a match at the tournament was Canada's Daniel Nestor who was 42 in 2014.
Earlier this year, Bopanna became the oldest ATP Masters 1000 champion when he won the Indian Wells doubles alongside Ebden.