A last-gasp goal from Sebastien Corchia saw ten-man Le Mans record a shock victory at Valenciennes to keep alive their faint hopes of Ligue 1 survival.
The match seemed destined for a stalemate following Guillaume Loriot's dismissal after the Le Mans captain was shown a second yellow card.
But Corchia curled in a superb winner in stoppage time to complete a fantastic week for Arnaud Cormier's men who snapped their four-match losing streak by holding title-chasing Montpellier to a draw last weekend before a shock midweek victory over Bordeaux.
Le Mans are now seven points off safety, having played a game more.
The visitors dominated from the start and could have taken an early lead when Modibo Maiga headed Corchia's free-kick inches wide.
Anthony Le Tallec tried his luck with a free-kick from just outside the area but VA goalkeeper Nicolas Penneteau got down for a decent save.
Penneteau pulled off an even better save seconds after the interval, somehow managing to prevent Mathieu Dossevi's shot from going in from extremely close range.
The Valenciennes goalkeeper was finally beaten on the hour mark but Maiga's header crashed off the right upright.
Le Mans were almost made to pay for their profligacy four minutes later as Didier Ovono pulled off a superb save to parry Gael Danic's effort but only as far as Gregory Pujol who volleyed it back goalbound.
Ovono denied VA again only for the ball to roll along the line where, fortunately for the visitors, Corchia was able to clear.
Le Mans had only picked up four points on their travels and looked set to face further misery when Loriot was shown a second yellow for protests.
However, in the second minute of stoppage time, Corchia curled a free-kick around the wall, which hit the base of the upright before rolling along the line and between the posts.