Roger Federer faces an uphill task to qualify for the last four of the ATP Finals after defeat by Dominic Thiem on Sunday following a masterclass by Novak Djokovic, reports AFP.
Six-time champion Federer was beaten 7-5, 7-5 in the evening match on the opening day after Djokovic had swatted aside debutant Matteo Berrettini in the earlier Group Bjorn Borg contest in London.
Federer and Djokovic will meet later in the week in a repeat of this year's epic Wimbledon final, with two players advancing from the four-man group. The Swiss 20-time Grand Slam winner recovered quickly from being broken in the first game of the match but the Austrian fifth seed repeated the dose in the 11th game and took the opening set 7-5.
"I thought Dominic saved himself real well when he had to," said Federer. "So I thought he played a tough first-round performance today, and my game was probably just not good enough, and the start didn't help."
"It's a normal tournament from here on forward," added the 38-year-old, who may now have to beat Djokovic to progress.