Novak Djokovic returned to action with an "ugly" win over Ivan Gakhov in the second round of the Monte Carlo Masters on Tuesday.

The world number one was competing for the first time in five weeks after missing the Indian Wells Open and Miami Open due to being unable to enter the United States.

Djokovic, who has since been cleared to compete in the US Open later this year, faced a spirited challenge from world number 198 Ivan Gakhov but advanced 7-6 (7-5) 6-2.

Gakhov broke his somewhat rusty opponent in the seventh game, but Djokovic hit back instantly as the opening set went to a tie-break.

The Serbian appeared rattled at various points, but an unforced error from Gakhov paved the way for Djokovic to open up some day light and take the opener.

The second set went the way of serve until the fifth game, when a double fault from Gakhov gave his opponent the chance to capitalise and see out the win.

"It was probably, if you can call it this way, an ugly tennis win for me today," Djokovic said in his on-court interview. "I haven't played my best, particularly in the first set. 

"And I kind of expected that that was going to happen in a way with swirly conditions, a lot of wind today, changing directions.

"It's different practising and then playing an official match on clay, where I guess no two bounces are the same. It's always quite unpredictable what's going to happen. 

"But all in all, I'm just pleased with the way I held my nerves I think in the important moments and I managed to clinch the two-set win."

Defending champion Stefanos Tsitsipas also advanced to the last 16 with a walkover win over Benjamin Bonzi, who retired with a wrist injury when 4-1 down in the opening set.

Fifth seed Andrey Rublev had a tougher time of things against Jaume Munar as he recovered from a set down to progress 4-6 6-2 6-2

Hubert Hurkacz was the other seeded player in action on Tuesday and defeated Jack Draper 6-3 6-7 (7-3) 7-5.