Olympique Marseille drew to miss out going back to the top of Ligue 1 on Sunday, while Lyon's title hopes also suffered a blow.
Lille went to the summit of Ligue 1 with a 5-0 thrashing of relegated Arles Avignon on Saturday, a result which had put pressure on Marseille to perform against struggling Auxerre.
The champions seemed to be heading back to the top when Mathieu Valbuena calmly netted at the far post on 56 minutes.
But South Korean striker Jung Jo-gook latched on to a long ball over the top to score 13 minutes before the end to salvage a draw for the visitors.
The draw means that - with five matches left - Lille now lead Marseille by a point and also have a seven-point advantage over third-placed Lyon, who meekly went down 2-0 at Toulouse.
Mauro Cetto's first-half effort and an Aly Cissokho own goal after the break were sufficient to hand the three points to Toulouse, who began the day flirting dangerously with the relegation zone but end it in the relative comfort of mid-table.
Michel Bastos and Cissokho then saw red in the second half to cap a miserable day for the visitors.
Caen boosted their survival hopes with a thumping 4-0 victory at 10-man Nice to move out of the relegation zone.
Romain Hamouma put the visitors ahead after 34 minutes and Yohan Mollo doubled their advantage on the stroke of half-time - immediately after the dismissal of Renato Civelli.
It looked to finish 2-0 but Hamouma and Youssef El Arabi were on target in the final two minutes to add further gloss to the scoreline.
The victory saw Caen climb above their hosts, who had started the day in 14th, on goal difference.
Montpellier's chances of qualifying for European football next season suffered a dent as they were held to a goalless stalemate against Brest.
Marco Estrada's late long-range strike was chalked off after the referee blew for an infringement, depriving the game of a rare moment of class.
This season's top six will qualify for continental action but the result leaves the hosts four places and three points outside that bracket.
In the late kick-off, St-Etienne were held to a 1-1 stalemate by Monaco.
Dimitri Payet put the hosts in front on 11 minutes but Monaco levelled via Georgie Welcome 20 minutes later.
The visitors had to play the last half an hour with ten men after Layvin Kurzuma was sent off for a second bookable offence but they held on to secure a valuable draw which lifts them a point above the drop zone.