Laurent Blanc's side knew a win would see them clinch a second successive crown, but they were forced to settle for a point against a Sochaux outfit battling for their lives.
It all looked to be going to plan for the defending champions when Edinson Cavani controlled Thiago Motta's lofted pass and volleyed into the bottom corner in the 24th minute.
However, the hosts levelled 11 minutes after the break when goalkeeper Salvatore Sirigu palmed Florian Marange's cross off PSG defender Thiago Silva and into the net.
The draw means Blanc's men now have to wait until May 7 for their next chance to win the title, knowing a win against Rennes will be enough, although they could be crowned champions before they play if Monaco fail to beat Guingamp on the same day.
For Herve Renard's Sochaux, the draw extended their unbeaten run to five matches and leaves them 18th in the table, four points adrift of safety.
Lille took a huge leap to securing UEFA Champions League football next season as they got the better of Bordeaux 2-1 at the Stade Pierre-Mauroy.
Salomon Kalou gave them the lead midway through the first half, before Ryan Mendes doubled their advantage in the 68th minute.
They were pegged back three minutes later when Jussie converted from the spot, but Rene Girard's men held on and currently lie third, seven points clear of Saint Etienne with three matches remaining, despite Kalou missing a late penaty.
Elsewhere, Lyon remain in the hunt for a UEFA Europa League spot after they thumped mid-table Bastia 4-1 at the Stade de Gerland.
The hosts took a 2-0 lead into half-time thanks to goals from Bafetimbi Gomis and Nabil Fekir.
The visitors pulled one back two minutes after the break through Gianni Bruno, but Lyon's two-goal advantage was soon restored by Bakary Kone, before Alexandre Lacazette rounded off the scoring in the 64th minute.
The result moved Remi Garde's men back to within two points of Saint-Etienne in the race for fourth spot.
