Brest slipped nearer to Ligue 2 after defeat to Rennes today.
First-half goals from Abdoulaye Doucoure and Victor Montano did the damage and while Rennes remain in the top half of the table, Brest are concerned only with survival.
They are five points adrift of that line, though, a situation which would become even more bleak should Evian earn an unlikely result tomorrow against leaders Paris St Germain.
The hosts at least started in encouraging fashion today, Larsen Toure volleying just over from Bruno Grougi's cross.
But they fell behind before the half-hour mark as Burkina Faso playmaker Jonathan Pitroipa sent Doucoure in on goal and he fired low past goalkeeper Alexis Thebaux.
Grougi's free-kick was turned goalwards by Johan Martial but saved by Benoit Costil, and Brest fell further behind in the 37th minute.
Julien Feret was the provider with a well-judged pass which Montano nodded past Thebaux from close range to make it 2-0 at the interval.
Thebaux had to be at his best to prevent Doucoure making it three just five minutes after the break when the midfielder lashed Pitroipa's pass goalwards.
Brest should have cut the deficit in the 54th minute when the impressive Grougi crossed and Adama Ba inexplicably failed to convert from close range.
Another good pass from Grougi was superbly volleyed at goal by Benoit Lesoimier, only for Costil to produce an equally good save.
And Lesoimier turned provider a minute later when Ousmane Coulibaly forced an extraordinary point-blank save out of Costil.
It was not to be, though, for Brest, who must surely win their remaining home games against fellow strugglers Sochaux and Nancy if they are to stand any chance of preserving their top-flight status.