Third bottom Valenciennes are now just two points adrift of safety after they won 1-0 at 17th-placed Evian.
Valenciennes striker Majeed Waris proved to be the difference between the two sides, the Ghanaian giving the visitors the points in the 63rd minute as he found the net for the sixth time since joining on loan from Spartak Moscow in January.
Attacker Roy Contout opened the scoring after just seven minutes, and Herve Renard's side made sure of the win 11 minutes from time thanks to a header from Zambia defender Stoppila Sunzu.
Rennes suffered a 3-2 loss to Toulouse that leaves them only three points above the drop zone.
Philippe Montanier's men fell behind after 14 minutes when striker Ola Toivonen put through his own net, before Toulouse doubled their lead as midfielder Clement Chantome netted just before the interval.
Substitutes Nelson Oliveira and Abdoulaye Doucoure scored for Rennes either side of a strike from Toulouse defender Serge Aurier, whose fifth of the season effectively secured success for Alain Casanova's team.
Bottom club Ajaccio's marginal prospects of safety took another blow with a 2-1 home loss to Guingamp.
