Monaco were denied victory by Le Mans, who scored in added time to secure a 1-1 draw in Sunday's French championship 10th-round match.
Le Mans made the more positive start at home and created several threats, but Monaco gradually took control of the contest and eventually found a way through.
The visitors opened the scoring in the 40th minute after Mamadou Coulibaly capitalised on an error in the Le Mans defence before sending the ball into the net.
Le Mans pushed for an equaliser after the interval, and their pressure finally paid off deep into stoppage time.
Erwan Colas scored the late leveller to earn the hosts a share of the points and prevent Monaco from claiming victory.