Stefanos Tsitsipas became the youngest player since John McEnroe 41 years ago to win the ATP Finals on his tournament debut on Sunday. The 21-year-old Greek beat Dominic Thiem 6-7 (6-8) 6-2 7-6 (7-4) in two-and-a-half hours at the O2 Arena in London to lift the year-ending title. Tsitsipas also became the youngest winner of the tournament since Lleyton Hewitt, aged 20, won it in 2001.
It is the biggest title of his career and his third of the year, a sum of his growth and maturity over the course of a rollercoaster of a breakthrough year. It has been a remarkable 2019 for Tsitsipas where he beat the "Big Three" of Novak Djokovic, Rafael Nadal and Roger Federer.
During the title clash, Tsitsipas, the youngest of the eight qualifiers for the elite season-ender, displayed resilience and flair in equal measure to claim his biggest title to date. Thiem edged an intense first set full of powerful baseline rallies but Tsitsipas, the first Greek player to play in the event, was undaunted and responded in style. He surged into a 4-0 lead in the second set.
Thiem appeared to be flagging when he then trailed 3-1 in the deciding set before rediscovering his early spark. But he bounced back to win three straight games, but in the deciding set tie-break — the first since 2005 — Tsitsipas surged to a 4/0 lead. Thiem recovered to 4/4 but later hit a forehand into the net to give Tsitsipas a chance to wrap it up. Tsitsipas didn't need a second invitation to close out the biggest victory of his career.
Tsitsipas hit 34 winners and 16 unforced edging past Thiem's 34 and 40. In the final two sets, Tsitsipas remarkably tallied 20 winners and four unforced.
It was the fourth time in 50 editions of the Nitto ATP Finals that a title match was decided on a final-set tie-break (also 1988, 1995 and 2005).