Djokovic, playing in a pre-Wimbledon event for the first time since 2010, edged a tight first set 6-4.
He capitalised on his opponent's lapse in concentration midway through the second set to break for a 4-2 lead. From then on he encountered few complications on his way to wrap up the match which had started on Tuesday but was delayed due to rain.
The 30-year-old Serb has conceded he is in a slump having failed to capture any major titles since June 2016 when he won the French Open to become only the eighth man to win a title at the four Grand Slam venues in Melbourne, Paris, London and New York.
However since that triumph which made him the first man since Rod Laver in 1969 to hold all four Grand Slam titles, there has been nothing notable.
He lost surprisingly in the second round at the 2017 Australian Open - the venue for six of his 12 Grand Slam crowns - and was abject in his quarter-final defeat on 7 June at the 2017 French Open in June by Dominic Thiem - a man he had annihilated in the semi-final at the Italian Open final on 20 May.
"I expect a lot from myself and it's obvious that I'm not playing close to my best," said Djokovic after Roland Garros. "I know that but I am trying to work on my game. Sometimes it works and sometimes it doesn't.
"This is a whole new situation that I'm facing. In the last seven or eight months, I haven't won any big tournaments which hasn't happened in many years. It's not something that hasn't happened to other players. All the top players have been through it. I guess you've got to go through it and learn your lessons."
For the third Grand Slam event of the season at Wimbledon, Djokovic has been seeded second behind Andy Murray and ahead of Roger Federer and Rafael Nadal. The four have accounted for all of the Wimbledon titles since 2003 with Federer top of the league with seven triumphs.
The 35-year-old Swiss warmed up for his assault on a record eighth crown with a ninth title on 25 June at the Halle tournament in Germany while Nadal was on the practice courts following his 10th success at the French Open.