Greek youngster Stefanos Tsitsipas has claimed the season-ending ATP Finals with victory over Austrian Dominic Thiem.
The 21-year-old Tsitsipas came from a set down to secure a 6-7 (6-8) 6-2 7-6 (7-4) victory in London.
Tsitsipas is the youngest winner of the prestigious season-ending tournament since Lleyton Hewitt in 2001, and the youngest debutant to lift the trophy since John McEnroe in 1978.