Razak Boukari fired Rennes to the top of the French league by scoring in Saturday's 1-0 win at Montpellier.
Meanwhile, Paris Saint-Germain lost ground in the title race with a 1-0 defeat at Auxerre.
Rennes earned its fifth straight victory to top the standings, three points clear of Lille which visits Marseille on Sunday.
"We didn't have a very good game but in the end we take three points," Rennes striker Victor Hugo Montano told Europe 1 radio. "We were facing a team that doesn't give up.
"We don't create many chances but we convert them. Right now, luck is on our side. But we will have to do more because luck won't always be on our side."
In Auxerre, midfielder Kamel Chafni scored from a half-volley in the 85th.
PSG remained in fourth place, five points behind Rennes, but Marseille and Lyon could leapfrog the Parisian club on Sunday.
PSG was playing without its two strikers, Guillaume Hoarau and Mevlut Erding. Hoarau had the flu while Erding was nursing a calf injury.
Also on Saturday, it was: Caen 1, Saint-Etienne 0; Lorient 0, Nancy 0; Toulouse 0, Sochaux 1; Valenciennes 0, Monaco 0; Nice 0, Lens 0.
Caen forward Youssef El-Arabi raised his tally to 13 goals by finding the net in the second minute of stoppage time off a pass from Yohan Mollo.
"Those three points will do us some good for the remainder of the season," Caen midfielder Benjamin Nivet said. "I hope this victory will be like a springboard for us. We still need to get some points to be safe."
Caen was in 14th place, six points above the relegation zone, while Saint-Etienne lost its fourth straight game to drop to 10th place.
Sochaux forward Modibo Maiga notched his 11th goal this season, tucking home a low cross from David Sauget in the 64th.
Toulouse goalkeeper Matthieu Valverde was sent off in the 89th for bringing down Cedric Bakambu, who was clean through on goal.
Sochaux climbed to eighth place while Toulouse suffered its fourth straight defeat to slip to 12th.
All matches were officiated by referees from the third division as the French Football Federation decided to replace referees in charge of first-division matches this weekend after the refereeing union vowed to delay kickoff times by 15 minutes in protest against recent criticism.
On Sunday, Lyon hosts Arles-Avignon and Bordeaux faces Brest.
