Saint-Etienne pushed Sochaux further towards relegation on Sunday with a 3-1 home while Lyon rode their luck to defeat Guingamp as both clubs closed the gap on Lille.
The bitter Ligue 1 rivals won in contrasting fashion as Saint-Etienne move within two points of third placed Lille who play later on Sunday at Monaco.
Lyon scored early in the second half thanks to a shot scrambled home by Bafetimi Gomis and then withstood a ferocious Guingamp onslaught to win 1-0 and stay three behind Saint-Etienne.
At the Geoffroy-Guichard stadium, substitute Mevlut Erding opened the scoring for the home side just after half-time with a header before French midfielder Franck Tabanou doubled Saint-Etienne's lead five minutes later.
Edouard Butin gave Sochaux a lifeline with 24 minutes left as Herve Renard's side chased a first away win of the season, but Erding sealed the points in the 89th minute to lift Saint-Etienne within touching distance of the final Champions League spot.
Sochaux meanwhile remain second from bottom and six points from safety.
"After two wins away from home, we had the heart to do the job in front of our fans," said Tabanou.
"After Saturday's results, it was equally important to win and stay in the top half of the table. Now we have to prepare well for the trip to Lyon which will be a great match to play.
"At home, we have to demand respect from the opposition to take the three points which is what we did but we're going to play hard until the end of the season and then we'll have to wait and see."
Lille travel to second-placed Monaco in the weekend's final match.
Leaders Paris Saint-Germain defeated Lorient 1-0 on the road Friday and are 11 points clear.