Novak Djokovic celebrates after winning against John Isner during their men’s singles round-robin match on Monday. Image Credit: AFP

London: World No. 1 Novak Djokovic is hoping to exorcise the ghosts of last year and remain steady for a sixth title at the year-ending Nitto ATP Finals at The O2 Arena this weekend.

The 31-year-old Serbian notched his 50th win of the season to ease his way to an easy 6-4, 6-3 win and extend his domination over American John Isner in their opening round-robin match late on Monday to take his first step towards a sixth season-ending crown.

Watched by Juventus and Portugal star footballer Cristiano Ronaldo, Djokovic was at his best sweeping aside the 6ft 10ins American in straight sets in just 73 minutes. Going in with an 8-2 career advantage against Isner, Djokovic cashed in on the 33-year-old American’s error-ridden debut at the Finals with a break in the fifth handing him a tough first set in 43 minutes.

Isner improved in the second, but Djokovic only managed to raise him game further and a break in the seventh was enough to see him through ahead of his second group match against red-hot Alexander Zverev on Wednesday.

“I’m not too exhausted. I’m feeling fit physically and mentally. I’m looking forward to that match [against Zverev],” Djokovic said.

“Obviously the good thing about this tournament is that you have days in-between matches, and you’re guaranteed to play three matches in the group. I obviously put myself in a very good position with the group with a straight-sets win [against Isner]. I am looking forward to playing Zverev. It should be a great match. I think we played against each other only twice and we split wins. I played him recently in Shanghai, but he wasn’t at his best. I expect him to play better than he did in Shanghai.”

Djokovic has had an amazing season so far beginning with his win at Wimbledon followed by his triumph at the US Open to return to his familiar perch as world No. 1. The Serb has made 10 appearances at the ATP Finals, during which he has won the title five times starting in 2008 followed by four in a row from 2012 to 2015.

The last time Djokovic played at The O2 in the final two years back saw him lose against Britain’s Andy Murray. “It’s quite different. I haven’t been really thinking about it too much,” he said. “I didn’t go through that experience at all. It’s good thing that I’m kind of in the present moment and trying to take the most out of it. Two years ago I was playing really well up to maybe September. That’s where I started feeling emotionally empty on the court.

“Andy, of course, had an amazing streak in winning 20-plus matches in a row. It was a perfect finale playing for No. 1 spot of the world, year-end No. 1, at World Tour Finals at home for him. It was a great win for him.”