Ghana striker Abdul Majeed Waris scored on Thusday night in his side's 2-1 defeat at Troyes in the Ligue 1 promotion/relegation playoff first leg.
Waris found the back of the net in the 82nd minute to draw his side level after conceded on 37 minutes through Stephane Darbion.
But the Breton club were undone by Benjamin Nivet injury time goal.
The return leg will be played on Sunday, 28 May with the winner booking a Ligue 1 slot.
Lorient finished third bottom and are facing the side which placed third in the Ligue 2.