Tabanou shot from outside the box on 38 minutes to take his side to 50 points from 29 games, three adrift of third-placed Lille, after they had been pushed down to fifth following Saturday’s games.
Auxerre, who appointed Jean-Guy Wallemme as their new coach this week, are on 24 points, five from safety.
Koro Kone and Younousse Sankhare scored either side of the interval to help Dijon beat Caen 2-0 at home.
Dijon moved up to 13th on 33 points while Caen stayed 17th, just above the relegation zone, with 29 points.
Second-placed Paris St. Germain aim to claim back the top spot from Montpellier when they host Girondins Bordeaux later on Sunday (1900).