Kenyan forward Dennis Oliech exploited Sochaux's defensive fragility to claim his first Ligue 1 hat-trick as Auxerre came from behind to win 4-1 at Stade Abbe-Deschamps on Sunday.
Beaten 6-2 at home by Rennes on Wednesday, Sochaux made a quick start and went ahead in the second minute when Yassine Mikari lofted a ball behind the Auxerre defence that Modibo Maiga tucked away.
However, Sochaux's porousness was evident in the second half, with quick-fire goals from top scorer Alain Traore and Oliech turning the match on its head.
Traore claimed his sixth goal of the season in the 51st minute, with Oliech making it 2-1 barely a minute later after Sochaux goalkeeper Teddy Richert fluffed an attempted clearance just outside his area.
Static defending enabled Oliech to fire home in the 63rd minute, after his initial shot had been saved by Richert, before he completed his hat-trick four minutes later by converting Traore's left-wing centre.
Victory lifted Auxerre above Sochaux and Dijon into ninth place, demoting Sochaux to 11th.
The basement battle between Brest and Ajaccio ended in a 1-1 draw, leaving both teams in the bottom three.
Fifth-placed Rennes host Saint-Etienne in Sunday's late game, when victory for the hosts would take them level on points with co-leaders Lyon, Paris Saint-Germain and Toulouse.
Lyon put their mid-week 1-0 loss to Caen behind them on Saturday when they overwhelmed Bordeaux 3-1, with Bafetimbi Gomis on target twice and in-form Michel Bastos claiming his second goal of the season.
A well-worked Umut Bulut goal saw Toulouse edge Nancy 1-0, while PSG confirmed their title credentials with an impressive 3-0 victory at former leaders Montpellier.
Record signing Javier Pastore found the net twice, slamming home a fine volley in the 43rd minute to make it 2-0 before capitalising on an error from goalkeeper Geoffrey Jourdren to seal the win 10 minutes from time.
Joe Cole opened his Lille account with a stunning 25-yard shot against Lorient, but an injury-time equaliser from Kevin Monnet-Paquet saw the defending champions held to a fourth straight draw in all competitions.
Marseille were also undone by a stoppage-time goal, with Jose Saez's last-gasp equaliser earning Valenciennes a 1-1 draw that left Didier Deschamps' under-performing side in 13th place.