LONDON, Nov. 12 -- Austrian talent Dominic Thiem became the first player to reach the semifinals at ATP World Tour Finals after clinching a sensational win over world number two Novak Djokovic here on Tuesday.
Thiem stunned Swiss legend Roger Federer in straight sets last Sunday in his first match in Group Bjorn Borg, then came from behind to edge in-form Djokovic 6-7 (5), 6-3, 7-6 (5) this evening.
"This was really one of these special matches, what I've practiced all my life for, all my childhood for," said the 26-year-old Thiem, who reached the semifinals of the season finale for the first time after qualifying for the tournament four years in a row.
In the deciding set, Thiem and Djokovic both broke twice to make it 6-6. Thiem was 4-1 down in the tiebreak but chivalrously snatched five points consecutively to earn two match points. The five-time champion Djokovic managed to save the first one but could not resist the second after returning the ball outside.
"Probably it was the best match I ever played. It was a real classic and epic match which will happen from time to time at these big tournaments," said the world number five.
Djokovic agreed that Thiem just played a great match and "I have to put my hat down and congratulate him."
"I don't think I have experienced too many matches like this where my opponent just goes for every single shot," continued the Serbian. "I mean, he was unbelievable, and in some stages, it was just incredible that he was just literally smacking the ball as hard as he can and he was going in."
Earlier, Swiss legend Federer defeated tournament debutant Matteo Berrettini from Italy 7-6 (2), 6-3. As the six-time champion lost his first match to Thiem, he has to defeat Djokovic on Thursday to reach the semifinals.
The last round group match will be the 49th encounter between the two prolific players. Djokovic beat Federer in this year's Wimbledon final in a five-set thriller and leads the head-to-head 26-22.