Federer went down 7-5 7-5 to Thiem, who has didn’t qualify from the group levels in his three earlier appearances on the finish of season showpiece.
However the fifth seed went into the match with a Four-2 profession win report over the veteran Federer, who was nonetheless the favourite after his current match victory in Basel.
The Swiss 20-time grand slam winner made the worst doable begin as he was damaged within the first recreation of the match, however broke again to degree in a intently fought opener.
Thiem then broke once more within the 11th recreation earlier than serving out to take a one set lead.
Federer didn’t benefit from an early likelihood to interrupt within the second set earlier than it was the 11th recreation once more which proved decisive as he was simply damaged.
Third seed Federer compelled two break factors as he tried desperately to remain within the match, however Thiem stored his nerve to win on his second match level.
“It is superb to play towards in all probability one of the best participant of all time, however fortunately I’ve a reasonably good report towards him,” stated Thiem.
Federer, who final gained the match again in 2011, now faces an uphill process to maneuver out of the Bjorn Borg group, which additionally contains Novak Djokovic and Matteo Berrettini. He has not failed to succeed in the knockout levels of the match since 2008.
Djokovic bids for information
Six is the magic quantity for Djokovic on the ATP Finals this week and the Serbian wasted little time in securing his opening victory of the round-robin part earlier Sunday.
Djokovic is aiming to finish the 12 months as No.1 for a sixth time, equaling the report of American nice Pete Sampras, and for his sixth title on the season-ending finale, matching Federer.
He made mild work of Berrettini, profitable 6-2 6-1 in simply over an hour on the O2 Enviornment of their group opener.
Berretinni, the primary Italian man to succeed in the year-end championships since Corrado Barazzutti in 1978, got here out preventing and confirmed early indicators of his high quality to carry for one recreation all.
However he was undermined by 17 unforced errors within the first set as nerves performed their half, permitting Djokovic to interrupt twice and seal the set in 28 minutes.
Eighth seed Berrettini produced a few of his greatest play initially of the second, nevertheless it couldn’t forestall him being damaged twice as he trailed by a set and Four-Zero.
Djokovic dropped his personal serve to offer Berrettini a glimmer of hope, however a 3rd break of his 23-year-old opponent settled any nerves and he served out for victory in 62 minutes.
“It was not straightforward for him at his first Finals match, I knew he could be nervous at the start and I used my expertise to carry out effectively,” stated Djokovic as he mirrored on a snug victory.
Nadal faces powerful opener
To have an opportunity of overtaking Rafael Nadal on the prime of the rankings Djokovic should a minimum of attain the ultimate, however he has made an imposing begin.
Nadal, who needed to pull out of the Paris Masters, gained final week by Djokovic, with an damage that impacts his service, performs defending champion Alexander Zverev of their Andre Agassi Group opener Monday.
Germany’s Zverev surprised Djokovic in final 12 months’s closing to raise the title, however somewhat than act as a springboard for grand slam success it has been the outdated guard of Nadal and Djokovic who’ve shared these majors in 2019.
Stefanos Tsitsipas of Greece and Russian Daniil Medvedev are the opposite qualifiers for the eight-man match.