Rennes slumped to a 1-0 home defeat by Bordeaux in Ligue 1 on Friday, four days before hosting Chelsea in a key Champions League game.
Bordeaux prevailed through a first-half goal by Hatem Ben Arfa as Rennes, who hope to revive their hopes in Group E against the London club on Tuesday, slipped down to fourth in the league standings on 18 points from 11 games.
Ben Arfa danced around three Rennes defender before beating Alfred Gomis with a low shot from just inside the box nine minutes before the break.
The result put Bordeaux up to 11th on 15 points.
