Paris, Nov 1 (IANS): Andrey Rublev strengthened his ATP Finals chances on Tuesday after defeating big-serving American John Isner 6-2, 6-3 to reach the third round at the Paris Masters here.

The 25-year-old produced a strong returning performance against Isner, breaking three times and winning 83 per cent (10/12) of points on the American's second service to advance after 62 minutes. With his 49th victory of the season, Rublev has improved to 1-3 in his ATP Head2Head series against Isner.

"It is a really important win at this moment when I am fighting for Turin," Rublev said.

"I think I was a bit lucky. It was his first tournament since his bad injury. From the baseline I was feeling really confident. As soon as I was returning and the ball was in play, I felt I had an advantage and wasn't nervous."

Rublev is currently seventh in the 'ATP Live Race To Turin' with 3,530 points. He is in the final qualification spot for the prestigious year-end event, to be held from 13-20 November.

Rublev's closest challenger, Taylor Fritz, is in eighth, holding 2,955 points. The American, who defeated Alejandro Davidovich Fokina in his opening match, will next play Gilles Simon.

Ninth-placed Pole Hubert Hurkacz can also still qualify. The 25-year-old, who has 2,870 points, will face Frenchman Adrian Mannarino in the first round later on Tuesday. If Hurkacz can advance and then defeat either Holger Rune or Stan Wawrinka, he would face Rublev in the third round in Paris.

Rafael Nadal, Carlos Alcaraz, Casper Ruud, Stefanos Tsitsipas, Novak Djokovic and Daniil Medvedev have already qualified for the Nitto ATP Finals, with two spots left in the final week of the regular season.