Dominic Thiem stayed very much in the mix at the ATP World Tour Finals with a 6-3 1-6 6-4 victory over mercurial Frenchman Gael Monfils at the O2 Arena on Tuesday.

The Austrian weathered a mid-match storm when an apparently injured Monfils burst to life with some audacious tennis in the second set before he steadied to take the match in the third.

It means the 23-year-old will go into his final Ivan Lendl group match against Milos Raonic on Thursday with a chance of reaching the semi-finals.

Beaten by Novak Djokovic in his opening match, Thiem used his baseline power to boss the first set against an erratic opponent also making his debut at the event.

But the contest took a wild turn as Monfils changed tactics and began to let rip with some fearsome groundstrokes, levelling the match in what seemed the blink of an eye.

Thiem stuck to his gameplan, however, and kept his nose ahead in a fiercely contested third set.

Monfils saved three break points at 3-4 but Thiem sealed his maiden victory at the event when Monfils crumbled at 4-5 and served two double-faults.

Monfils also lost to Canada’s Milos Raonic in his opening match on Sunday and was hobbling at times, putting his continued participation in some doubt.

Djokovic and Raonic meet later on Tuesday with both looking to claim their second group victory.

Serbian Djokovic, bidding to reclaim the world No.1 ranking, leads 7-0 in their previous matches and has only dropped one set of 18 the two have played, at the 2014 Rome Masters.