London, Nov 23 (IANS): Russia's Daniil Medvedev won the ATP Finals, the biggest title of his career so far, after getting past US Open champion Dominic Thiem in a thrilling three-set summit clash.

On Sunday, the Russian fourth seed defeated Thiem 4-6, 7-6(2), 6-4 after two hours and 43 minutes to become the first player to beat each of the men who were numbered 1-3 in the season-ending championship -- and only the fourth to do it at any tour event in the past 30 years.

"I always said before this tournament that it would be an amazing story if, here in London, where the tournament was for (12) years, that the first champion would be Russian and the last champion would be Russian, too," Medvedev said after the match as per the ATP Tour website.

The 24-year-old is the first player from his country to win the year-end championships since Nikolay Davydenko in 2009.

"A lot of thanks to Nikolay Davydenko for being an inspiration for many kids (like) me (by) winning here. I hope to continue doing his job," said Medvedev.

Thiem, seeded third, did well to save the first eight break points he faced in the match, using his defense and power from the baseline. However, he flirted with danger way too often and was unable to recover against the Russian.

"I think it was the toughest victory in my life because Dominic is a really tough player to play. I think today he was at his best," Medvedev said. "Maybe it's not the case, but that's what I felt during the match. He was really close to winning it (in the) second set. I managed to stay there."

Thiem was trying to become the first player from his country to win the ATP Finals in singles or doubles. It is the second consecutive year he has suffered a heartbreaking loss at The O2. Last season, Stefanos Tsitsipas had defeated him in a final-set tie-break for the trophy.

"Of course, I am disappointed, but at the same time I am also proud of the performance of all the week. Daniil really deserved it," Thiem said after the match.