They had to settle for a three-way tie on 57 points with leaders Olympique Lyon and second-placed Montpellier. Auxerre are third on goal difference with seven games left.
Romania striker Daniel Niculae put Auxerre in front from inside the box in the 11th minute but their advantage was quickly cancelled out by Younousse Sankhare.
Lyon earned a 2-1 win at Stade Rennes while Montpellier were held 0-0 at home by Monaco on Saturday.
"We're disappointed to see we couldn't get three points but let's wait the end of the season before drawing any conclusion," Auxerre coach Jean Fernandez told Canal Plus television.
Olympique Marseille closed to within one point of the top three after a first-half header from Brandao secured a 1-0 victory at home to Racing Lens earlier on Sunday.
Marseille, who ended the game with 10 men after defender Stephane Mbia was sent off with 15 minutes left, are fifth on 56 points, behind fourth-placed Girondins Bordeaux on goal difference.
Both clubs have two games in hand.
Former leaders Bordeaux lost 2-1 at home to Nancy on Saturday.
AUXERRE FELT TIRED
Auxerre, the 1996 champions, opened the scoring early in the game when Niculae collected a cross from Ireneusz Jelen and fired a volley into the net from inside the box.
PSG equalised five minutes later thanks to Sankhare who scored his first goal in the top flight.
The 20-year-old midfielder tapped in from close range after forward Mevlut Erding forced a save from Auxerre goalkeeper Olivier Sorin, who could not catch the ball.
The Burgundy side pushed harder after the interval but Jelen's efforts all went wide.
"We started off well and had we held the lead longer, we would have threatened PSG more ... We were tired after the interval, especially Jelen, and that's what cost us a lot," said Fernandez.
Marseille failed to create many chances against Lens until Brandao headed home a Lucho Gonzalez corner kick midway through first half.
The game lacked pace and became more tense after the interval as Marseille were unable to threaten the visitors and then Mbia was sent off for a fierce challenge on Lens forward Issam Jemaa.
"The most important thing is the result and we got a good one. Even if we had to struggle, we reached our goal," Marseille coach Didier Deschamps told reporters.
"We started slowly against a team whose main intention was to defend ... but eventually, we were able to get a win.
"This is a good weekend for us as we are now closer to the top ... It's going to be tight until the end."
In other Ligue 1 action on Sunday, Toulouse snatched a 1-1 draw at Boulogne with a late equaliser by Norway midfielder Daniel Braaten, who fired home from the edge of the box.
Former France international Olivier Kapo had opened the sco
