World number one Novak Djokovic beat qualifier Ivan Gakhov in his first match in more than a month to reach the third round of the Monte Carlo Masters.
Djokovic, who received a first-round bye, beat the Russian 7-6 (7-5) 6-2.
He had not played since 3 March, when he lost to Daniil Medvedev in the Dubai Tennis Championships semi-finals.
The Serb was not allowed to enter the United States for the Miami Open and Indian Wells Masters because of his Covid-19 vaccination status.
Djokovic, a 22-time Grand Slam champion, will face either qualifier Luca Nardi or 16th seed Lorenzo Musetti, both of Italy, in the last 16 on the Monaco clay.
“It was probably an ugly tennis win today,” said the two-time Monte Carlo winner.
“I haven’t played my best, particularly in the first set, but I kind of expected that to happen in a way with the conditions, a lot of wind today.
“All in all, I am pleased with the way I held my nerve in the important moments.”
Djokovic’s defeat by Medvedev in Dubai continues to be his only loss of 2023 so far.
Elsewhere, British number two Dan Evans fell to an early exit with a 2-6 6-2 6-3 first-round defeat by Belarusian Ilya Ivashka.
Evans, ranked 28th in the world, had been looking to continue the form that saw him reach the semi-finals of the Grand Prix Hassan II last week but after dominating the first set – in which he won the opening four games – he lost control.
After Ivashka won the second set, doing so on his third set point, the 29-year-old comfortably saw out the decider, taking the last three games for his first Masters 1000 win on clay.
Ivashka will play his brother-in-law, Russian ninth seed Karen Khachanov, in the second round.