Stefanos Tsitsipas, who was the runner at this year's Dubai Duty Free Tennis Championship, has won the ATP Finals title.
He came from a set down to beat Dominic Thiem on Sunday night at the O2 Arena in London.
The 21-year-old from Greece took the match in a pulsating final-set tie-break.
Tsitsipas becomes the youngest winner of the season-ending ATP Finals in 18 years.


Top contender Sabalenka faces fresh scrutiny at Wimbledon as mental scars linger
Munoz strike sends Colombia into World Cup Round of 32
Qatar's sports minister, Madibo visit Canada's injured Kone
Budimir gives Croatia win to eliminate Panama in Group L
England fail to break down Ghana in goalless draw
