Paul Baysse scored the only goal of the game as Brest recorded a 1-0 win over Marseille on Sunday evening.
Marseille came close to opening the scoring after five minutes with an effort from Morgan Amalfitano, but his strike was blocked by Baysse.
The away side again went close through Mathieu Valbuena and Amalfitano, but both saw their efforts drift wide.
Brest took the lead entirely against the run of play when Baysse thumped a header into the top corner after 16 minutes.
It was Marseille who continued to dominate in the opening half, however, with Charles Kabore and Brandao both coming close, but Brest continued to resist the pressure.
Brest came close to extending their lead after 55 minutes when Dialo Guidileye advanced on goal, but his effort was beaten away by Steve Mandanda.
Marseille's best chance of the second period fell to Benoit Cheyrou after 68 minutes, but his strike from outside the area drifted just wide of the post.
Andre Ayew missed a golden opportunity to level the match after 81 minutes, but his header was wide of the post.
Brest will look to build on the result when they face Caen next Sunday, while Marseille host Toulouse.