Stefanos Tsitsipas secured a 6-7 (6), 6-2, 7-6 (4) victory over Dominic Thiem to win the ATP Finals for the biggest title of his career. The 21-year-old is now the youngest winner of the season-ending tournament since 2001 when Lleyton Hewitt won the title and the youngest debutant to win the trophy since John McEnroe in 1978.

Only one year after winning the NextGen ATP Finals, Tsitsipas has established himself at the top of the big leagues. He even pulled out a v semifinals win over Roger Federer, 6-3, 6-4. 

It was only the third time in 16 years that an ATP Finals champion wasn't one of the Big Three.