Greek tennis player Stefanos Tsitsipas won the ATP Finals title, beating Dominic Thiem 6-7 (6), 6-2, 7-6 (4) at the 02 Centre in London on Sunday evening.
Despite only dropping only three points in his opening three service games, Tsitsipas, 21, suffered an early setback against the Austrian, losing the first set, which was punctuated by many powerful baseline rallies.
But the world number six came back in the second set, after Thiem appeared to tire slightly, winning it 6-2 in only 29 minutes.
Thiem started the third set off solidly, but after Tsitsipas broke him on the third game, he was on the back foot.
The Austrian managed to level the set at 3-3 but it wasn’t enough. Tsitsipas's phenomenal serving helped him bring the set to a tie break, where he held his nerve to win the championship.
"I have no clue how I played so well in the second set," he said on court after the game. "I was nervous playing in such a big event.
"But I'm so relieved by the outstanding performance and the fight I showed today."
Tsitsipas is the youngest of eight qualifiers in the elite end-of-season finale at the 02 arena, and the youngest to win since Australian Lleyton Hewitt took it out in 2001.
Tsitsipas is also the youngest player to reach the final on debut since American Jim Courier in 1991.
He beat six-time champion Roger Federer in straight sets in the semi-finals on Saturday, marking the second time he had beaten the Swiss veteran in four games.
Thiem beat six-time champion Roger Federer and five-time winner Novak Djokovic in the group stage but lost another big final after twice finishing runner-up to Rafael Nadal at the French Open.
Sunday's game marked only three of 16 ATP finals that didn't feature the big three – Djokovic, Federer and Nadal – indicating that the top-calibre players may finally be shifting in male singles.
”It was so close,” Thiem said. ”But that’s how it is in tennis.”
