LONDON, Nov. 13 (Xinhua) -- Bulgaria's Grigor Dimitrov beat fourth-seeded Dominic Thiem of Austria at the ATP World Tour Finals 6-3, 5-7, 7-5 at the O2 Arena here on Monday.
The sixth seed broke Thiem three times, including late in the third set when Thiem was serving at 5-5 (0-30) when he double faulted twice to hand Dimitrov the break.
Dimitrov, playing his first match at the ATP Finals, fell behind 0-15 at 6-5 but converted on his third match point for the win.
"It, for me, was just one of those new experiences that I think I'm going to remember for the rest of my life, I think appreciate for the rest of my life," Dimitrov said. "This is where I always wanted to be at, among the top players, also being able to come through in my first match, it's only positive."
Thiem, playing in London for the second consecutive year, saw his record drop to 2-1 against Dimitrov, whom he saved five match points to beat at the Madrid Open earlier this year.
"There's always a little bit of tension before every match, and especially here, of course, a little bit because of all the atmosphere, arena. Also because it's your first match, and it's against a really, really good opponent, so you're very tense," Thiem said.