Mamadou Niang exploited a goalkeeping gaffe by Ulrich Rame in first-half injury time to put OM in front but Wendel's superb 80th-minute free-kick brought Les Girondins level.

And substitute Ducasse unleashed a ferocious long-range effort with seconds remaining to complete the comeback and fling the title race open with two games left.

The result means OM stay fourth, two points adrift of Nancy in the battle for the final Champions League spot.

Fifth place remains up for grabs after UEFA Cup hopefuls St Etienne and Lille drew a blank at the Stade Geoffrey-Guichard earlier on Sunday.