Serbia's Novak Djokovic [Source: Reuters]

Defending champion Novak Djokovic shrugged off doubts about the state of his game with a confident 6-4 7-6(3) 6-4 defeat of Pierre-Hugues Herbert in the French Open first round on Tuesday.

The top seed had to wait until the night match on the third day of the tournament to begin his quest for an Open era record-extending 25th Grand Slam title but quickly hit his stride to dispatch French wildcard Herbert on Court Philippe Chatrier.

Djokovic, 37, has not reached a final this year and his world number one ranking is under threat from Jannik Sinner.

But everything looked in fine working order against Herbert who put up solid resistance but never looked likely to unduly concern the Serbian who has now won 72 of his 74 first-round matches in Grand Slam tournaments.

The only blip came in the second set when Djokovic broke serve early but then dropped his own and was dragged into a tiebreak before finding an extra gear to move towards victory.

Defeats in Rome and Geneva to Alejandro Tabilo and Tomas Machac respectively led Djokovic to say he had high hopes but low expectations for the French Open.

But while he may have played down his chances, Grand Slam tournaments are a different proposition.

Djokovic broke Herbert’s serve early in the opening set with a thumping forehand winner and took the opener in 37 minutes.

But he temporarily lost his way in the second set as Herbert, who has two French Open doubles titles to his name, began to vary his serving and raid the net to knock Djokovic out of cruise control.

The top seed played a near-faultless tiebreak, roaring his approval after several points, and after that it was something of a formality despite Herbert’s gritty resistance.

Djokovic set up match point with a sublime backhand winner and Herbert served up a double fault to end the contest.

Three-time Roland Garros champion Djokovic will face Spain’s Roberto Carballes Baena in round two.