Djokovic, a six-times winner at the ATP Masters 1000 event in the French capital, was made to toil in the opening set by Cressy but emerged unscathed after the American double-faulted twice in the tiebreak.

The Serbian raised his game in the second set, breaking his opponent at 4-4 before serving out the match with ease.

"It was very intense, just a lot of pressure," said 21-times major champion Djokovic.

"When you play someone that serves this well - first and second serve - you don't have much room to relax and maybe play kind of a softer few games.

"A break came at the right time, perfect time actually. I was very pleased with the way I held my serve, didn't face a break point."

Earlier, Rublev was solid on return as he broke the big-serving John Isner three times to progress 6-2 6-3 in just over an hour and claim his first win in four career meetings against the American.

"It is a really important win at this moment when I am fighting for Turin," said the 25-year-old, who is vying for one of the two remaining spots at the season-ending ATP Finals.

"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."

Poland's Hurkacz fired 20 aces and saved eight break points to overcome French left-hander Adrian Mannarino 7-6 (7-5) 6-4 to stay on course for a potential third-round clash against Rublev.

Third-seeded Casper Ruud, who has already qualified for the ATP Finals, defeated French wild card Richard Gasquet 6-1 7-6 (9-7) after a thrilling second set in which the Norwegian bounced back from 5-3 down.

In the other matches, French qualifier Corentin Moutet downed Borna Coric 3-6 6-3 6-4 and Dan Evans of Britain saw off American youngster Brandon Nakashima 6-3 3-6 6-4.

Australian Associated Press