Gignac bags brace in Toulouse triumph
The France striker, who was Ligue 1 top scorer last season, found the back of the net twice just after the interval as Toulouse moved up to ninth on 24 points.
Girondins Bordeaux lead the table on 31 points.
Toulouse missed their three professional goalkeepers through injuries and they had to field 17-year-old trainee Anthony Loustallot. He did not have much work to do against Sochaux, who lie 15th on 19 points.
Lille grabbed a fifth win in their last six league games when they humbled 4-0 strugglers St Etienne. They are eighth on 25 points.
Pierre-Alain Frau opened the scoring in first half before midfielder Yohan Cabaye made it 2-0 from the spot after the interval.
Gervinho, from Ivory Coast, capitalised on a corner kick by Cabaye and defender Adil Rami sealed Lille's win with a long-range free kick.
Both Frau and Gervinho have now scored eight goals in Ligue 1 this season, two behind top scorer Nene from Monaco. St Etienne are one place above the drop zone on 15 points.