Le Mans' five-year stay in Ligue 1 was ended tonight as defeat at Nancy ensured they were relegated to Ligue 2.
Arnaud Cormier's side started the match seven points adrift of St Etienne with three games remaining, but St Etienne's victory at Boulogne secured their own safety and sent Le Mans down and rendering the defeat at Nancy meaningless.
In a thrilling match at Stade Marcel Picot, Nancy took the lead in the 17th minute through Julien Feret before Modibo Maiga levelled six minutes later when he tapped the ball into an empty net.
Le Mans were then given hope of survival when Mathieu Dossevi pounced two minutes later but Feret claimed his second of the game 14 minutes before the interval.
Chris Malonga put Nancy back in front with half an hour left and, although, Anthony Le Tallec hit the bar for Le Mans, they could not force another goal and their fate was sealed.
It was the visitors who had the first opportunity with Dossevi firing narrowly over before Feret hit into the side netting with only the goalkeeper to beat for Nancy.
Feret soon made amends when he fired home a powerful shot from Jonathan Brison's cross.
But Maiga levelled when he pounced after goalkeeper Damien Grgorini pushed the ball out near his post and two minutes later the visitors were ahead.
Ludovic Baal's snap-shot was parried by Grgorini with Dossevi on hand to slot the ball into an empty net.
The lead was soon nullified when an unmarked Feret volleyed home from close range.
Nancy retook the lead when Malonga headed home.
With a little over 10 minutes left Le Tallec unleashed a curling shot which came back off the bar and they almost conceded another in stoppage time when Didier Ovono was forced to go at full stretch to keep out Youssouf Hadji's shot.