Two late strikes from Jimmy Briand sewed up all three points for Rennes after they had been pegged back by hosts Le Mans.
Ismael Bangoura scored a first-half penalty and after Mathieu Dossevi had levelled, Briand struck in the last five minutes to keep Le Mans deep in relegation trouble.
The home side had started the match second bottom in Ligue 1 but even the appointment of general manager Michel Moulin could not inspire them to a much needed victory.
The home side nearly got off to a perfect start when Sebastian Corchia saw his cross miss Anthony Le Tallec but find Roland Lamah at the far post, only for his half-volley to go wide.
Modibo Maiga crossed from the left and Mathieu Dossevi timed his run to the near post well but goalkeeper Nicolas Douchez rushed off his line to beat him to the ball.
Briand created the first opening for the visitors after 20 minutes when he set up Sylvain Marveaux but his shot on the turn brought a fine save out of Didier Ovono who pushed the ball out for a corner.
Rennes' Corchia then cleared off his own line after a long ball caused confusion between Ovono and Briand who had headed the ball over his own keeper.
Rennes took the lead six minutes into the second half when Marveaux weaved his way into the Le Mans area.
Keeper Ovono brought the Rennes player down for a penalty and Ismael Bangoura stepped up to put the visitors ahead from the spot.
But Le Mans did not take long to level the scores as six minutes later a poor clearance by the Rennes defence saw Frederic Thomas attempt a volley.
His effort was off target but the ball fell to Dossevi who controlled before shooting low past Nicolas Douchez in the Rennes goal.
Rennes retook the lead with 17 minutes remaining when Rod Fanni was released down the right and his cross was met at the near post by Briand who directed the ball home with a fine header.
With five minutes remaining Rennes wrapped up the three points when Briand netted his second goal.
Carlos Bocanegra played a long ball which Briand got to ahead of the Le Mans defence and then he poked it past Ovono.