The Serbian triumphed 4-6, 6-1, 6-4 over Youzhny in Monaco, in his first game back after suffering the ankle injury in a Davis Cup match against American Sam Querrey in early April.
Earlier in the week, Djokovic said on Twitter: “I have good news. I will be playing tomorrow in Monte Carlo, my first match.
“I’m very excited about it, to be honest, because in the last six, seven days I’ve been doing everything in my power, after the incident in the Davis Cup, in order to recover.
“My ankle is in a state that is good enough for me to perform. Hopefully I can perform my best and win, and I can see how it goes day by day.”