Mevlut Erding's first goal for Rennes was enough to claim all three points against bottom side Sochaux.
The Turkish forward, who signed from Paris St-Germain in January, headed in a Jonathan Pitroipa cross after 16 minutes.
Although Frédéric Antonetti's side were well worth their half-time lead, they were made to sweat for the win after the break.
Sochaux piled forward in search of an equaliser; Sloan Privat and Ryad Boudebouz went close but Rennes hung on.
Rennes have temporarily gone level on points with Lille, who occupy the final Champions League place.
