Marseille missed the chance to keep pace with rivals Lille after being held at home by mid-table Valenciennes FC.
Les Phoceens went ahead through a header from one-time Liverpool midfielder Alou Diarra, who met Rod Fanni's cross after 16 minutes.
Jordan Ayew was unlucky not to have made it two moments later. His smart chip beat keeper Nicolas Penneteau but was unable to beat the crossbar.
Valenciennes hit back in the 51st minute, when a corner seemingly evaded everyone before falling to Carlos Gil, who slammed it into the net from close range.
Marseille missed a chance to win the game in the last minute when Brazilian forward Brandao headed against the post.
The stalemate means that Marseille remain in fourth place, and extend their unbeaten run to 15 games. Valenciennes drop to 11th courtesy of Dijon's victory over Nice.
Next up for Marseille is a trip to Brest, and Valenciennes have a home fixture against Lorient.
