Novak Djokovic kicked off his quest for a sixth Italian Open title and the defence of his world number one ranking with a 6-3 6-2 victory over Aslan Karatsev in the second round on Tuesday.
Top seed Djokovic, who received a bye into the second round, is still seeking his first title of the year.
If Djokovic does not reach the semi-finals in Rome, he will surrender top spot in the rankings to Russian Daniil Medvedev for a second time this year.
The Serb, however, got the job done against Karatsev, who had beaten him in Belgrade last year.
"He's a very strong guy, just solid from the baseline. You never know with him. If he's feeling the ball, it can be very dangerous because he stays so close to the line and puts pressure on his opponents," Djokovic said.
"He was missing a lot of balls today though. He gave me a couple of breaks... I'll take this win, it's a straight sets win against a quality opponent."
Djokovic brought the crowd to its feet at one point, sprinting from one end of the court to the other, scrambling and sliding to reach for an outrageous drop shot at the net before opening up the court for a winner.
"Obviously that's what the crowd is looking for -- energy, excitement, they're looking for fight. They want to see some good tennis," the 34-year-old said with a smile.
"We had some nice points today. It's always great to play in the Colosseum of tennis."
Earlier, 2020 runner-up Diego Schwartzman saved two match points to edge Miomir Kecmanovic 6-2 3-6 7-6(3) to move into the second round while David Goffin upset 11th seed Hubert Hurkacz 7-6(8) 7-6(2).