A goal late in the first half from Mevlut Erding saw Rennes claim their fourth win of the season and leapfrog 10-man Reims in Ligue 1.
However, the visitors deserve some credit for conceding a solitary goal given they had to play for 76 minutes with 10 men following the sending off of Pape N'Diaye Soure for a nasty challenge on Jonathan Pitroipa.
With just five minutes to go until half time, the hosts went ahead when Erding headed home.
Victory guided Rennes to eighth, one ahead of their opponents.
Rennes had the first real shot on goal, Jean Makoun finding Pitroipa who chested the ball down and volleyed only inches wide.
The pendulum then swung in Rennes' favour when Soure was given a straight red card but it was the visitors who then came closest. Diego Rodrigo Rigonato produced a left-footed cross shot which pulled a fine save from Benoit Costil at the near post.
Romain Alessandrini sent in a low 20-yard shot for Rennes forcing Kossi Agassa to go down and make a block.
Reims appeared likely to hold on until half-time but five minutes before the break, Alessandrini's corner found Erding at the near post and he glanced the ball into the net.
The visitors almost levelled immediately after half-time when Rigonato's powerful 30-yard drive hit Makoun in the face, the ball deflected away.
Antony Weber then freed Antoine Devaux whose long-range shot was on target but Costil gathered.
From there on Rennes dominated. Erding sent a fierce shot inches over the bar, Abdoulaye Diallo's header forced Agassa into a fine reflex save with the keeper then thwarting Erding.