U.S. striker Folarin Balogun scored his third goal of the season for Monaco since his summer switch from Arsenal, but refused to celebrate against the team where he left his mark last season.
The Monegasques moved top of Ligue 1 on Saturday after Balogun, Ismail Jakobs, and Wissam Ben Yedder scored against fourth-placed Reims in a 3-1 away game.
Monaco took the lead just before halftime when defender Jakobs netted from close range for his first Ligue 1 goal since he joined the club from Cologne in 2021.
Balogun doubled the lead for the visitors early in the second half with a fine finish from close range despite a deflection.