Novak Djokovic dispatches Matteo Berrettini to kick-off in style — ATP Finals

Novak Djokovic on battling for year-end No. 1 spot

Novak Djokovic on battling for year-end No. 1 spot

On the verge of an nearly flawless performance against Matteo Berrettini at the ATP Finals, Novak Djokovic still found a reason to berate himself.

The Serb was imperious, beating Italian eight seed Matteo Berrettini 6-2 6-1.

Even at the end of another grueling season, Djokovic won't tolerate any dips in his game as he pursues a record-equaling sixth ATP Finals title.

Federer, Nadal and Djokovic were the top three seeds when they first competed together at the tournament way back in 2007 and are still the men to beat 12 years later.

Matteo Berrettini of Italy plays a backhand during his debut against Novak Djokovic at the ATP Finals.

Djokovic romped into a 4-0 lead in the second set as the Italian continued to struggle with his serve but was pegged back in the fifth game as Berrettini broke for the first time.

Berrettini claimed a brilliant point in game two of the second set, managing to reach for a low backhand that Djokovic could only skew into the air, providing his opponent with a simple volley.

"It was not easy for him at his first Finals match, I knew he would be nervous at the beginning and I used my experience to perform well". Roger got broken at love in the 11th game following a deep return from Thiem who fended off a couple of break chances with good first serves in the next game to convert the second match point with a service victor that carried him over the top.

"I've been enjoying the conditions here for many years", he added. "I think I started the match pretty good, but he was just better than me today".

Federer, bidding to win a record seventh title at the season-ending event, takes on Austrian Dominic Thiem in the evening match.

Nadal, Daniil Medvedev, Stefanos Tsitsipas and Zverev are in the Andre Agassi group.

Djokovic must reach the final at the O2 Arena to stand any chance of dislodging Nadal but there are major questions over the Spaniard's fitness.

The Serbian was last week nudged off the top position in the rankings by Rafael Nadal, who is also in the eight-man field in London.