Auxerre upset leaders Bordeaux
Defender Benoit Tremoulinas put Bordeaux ahead with a shot that took a deflection off Auxerre midfielder Benoit Pedretti on six minutes.
Auxerre, who had beaten Bordeaux 1-0 earlier this season, stepped up a gear after the break and levelled on 64 minutes courtesy of Jelen, who was on target again seven minutes from time when he headed home the winner after his shot bounced off the crossbar.
Bordeaux, who have looked below par in recent outings and had been held to a 1-1 home draw by Montpellier last Sunday, failed to use one of the two games they had in hand to move clear and stayed on 52 points, now from 26 games.
Montpellier, back in the top flight this season after a long spell in the second division, lie second on goal difference, with Auxerre, who have also played one more game than Bordeaux, one point off the pace.