Auxerre were held to a sixth draw in their nine Ligue 1 games this season despite taking an early lead at the Stade Geoffroy-Guichard this evening.
Ben Sahar struck after five minutes and Anthony Le Tallec was denied a second by an erroneous offside flag just seven minutes later.
But Josua Guilavogui equalised before half-time and each team hit the woodwork in the second half as an entertaining encounter ended all square.
Defender Jeremy Clement was culpable as Auxerre took an early lead when he was caught in possession by Le Tallec, who raced into the box and set up Sahar to finished right-footed.
The pair linked up again in the 12th minute, Sahar picking out Le Tallec in the box, and he slotted home but the flag went up. The visiting fans were incensed, however, and replays indicated Le Tallec was clearly onside.
St Etienne's first effort of note came when Pierre-Emerick Aubameyang ran unchallenged to the edge of the box and shot inches wide.
But they equalised in the 38th minute when Loris Nery's cross was headed against the post by Lynel Kitambala and Guilavogui followed up to head home.
The hosts almost led two minutes into the second period but Bakary Sako's thunderous left-foot shot rebounded off the upright.
And it was Le Tallec's turn to hit the post in the 67th minute with a left-foot effort from Dennis Oliech's flick-on.
Auxerre defender Amadou Sidibe had to stand firm to deflect Aubameyang's effort behind two minutes later.
Both sides had chances to win it in the last 10 minutes, starting with Auxerre as Oliech met Omar Kossoko's cross but shot straight at Stephane Ruffier.
The home side's chance came from a free-kick with five minutes left, but keeper Olivier Sorin kept out both that effort and Aubameyang's follow-up.