Kevin Monnet-Paquet, who moved to his new club from Lorient in the summer, was the next player to come close to breaking the deadlock when he fired just wide of the target following an impressive solo run.
Van Wolfswinkel's frustrating evening in front of goal continued before the break as Lecomte charged off his line to deny the former Norwich City forward, who had timed his run perfectly to beat the offside trap.
© Getty Images
Lorient were unable to stop Saint-Etienne's dominance in the second half as the hosts offered very little in the final third of the pitch.
It looked as if Lorient might snatch victory themselves late on as Max Gradel fired a great chance over the crossbar from Pacquet's cross.
However, Lemoine would have the final say as he took full advantage of the space offered by the Lorient defenders to pick out the top corner from 25 yards and send his side to fourth in the table.