Alexander Zverev showed signs of a return to his explosive best in a 6-1 6-4 win over Felix Auger-Aliassime.
Zverev, who lives in Monte Carlo, reached the semi-finals of his 'home' event a year ago, but has endured a difficult 2019 season.
After finishing runner-up to Nick Kyrgios in Acapulco, Zverev has suffered early exits at Indian Wells, Miami and Marrakech.
"This is the first time this season I've felt really healthy," said the 21-year-old.
"I've been training well but haven't been able to take that into matches.
"I live just 500 meters from here, I'm comfortable on this court. I'm starting to feel better about my game. I'm really ready for the clay season."
Last year's French Open runner-up Dominic Thiem won 20 of his 23 first-serve points in a commanding display to beat Slovakian Martin Klizan 6-1 6-4.
Article from Reuters
