Second-half goals from Mathieu Dossevi and Gregory Pujol lifted Valenciennes off the foot of Ligue 1 as they earned their first win since the opening day of the season at fellow strugglers Ajaccio.
Ariel Jacobs' men have plummeted down the table since beating Toulouse in their first match, losing eight and drawing twice, although they took a 26th-minute lead through Pujol.
Although Rudy Mater's own goal just after the half-hour mark levelled proceedings, Dossevi put the visitors ahead once again in the 67th minute before Pujol scored his second in the closing stages.
It was a much-needed win for Valenciennes although the pressure is now mounting on Ajaccio boss Fabrizio Ravanelli following a fourth successive defeat.
Gadji Tallo went closest for the hosts in the opening stages, firing just wide after being picked out by Benoit Pedretti.
Valenciennes, whose Coupe de la Ligue loss to Troyes in mid-week was branded as embarrassing by boss Jacobs, responded, with Marco Da Silva seeing a free-kick skim the top of the crossbar.
The visitors would not be denied, however, and took the lead on 26 minutes when Pujol expertly slammed home a volley from Israel international Maor Melikson's pinpoint cross from the left.
Their lead lasted just six minutes as former chelsea and Juventus forward Adrian Mutu's free-kick was headed on by Ronald Zubar before Valenciennes defender Mater grabbed a decisive final touch following his attempted clearance.
Chances were few and far between up until the hour mark, when Pujol was only denied his and Valenciennes' second by a fine save from Ajaccio goalkeeper Guillermo Ochoa, whose opposite number Nicolas Penneteau then did well to deny Mutu's header at the other end.
It proved a crucial save as Dossevi gave the visitors the lead for the second time in the match, heading home from Pujol's chip into the box on the right.
Mutu once again saw a header kept out by Penneteau and Pujol made sure there was no way back for Ajaccio in the second minute of injury time.
The 33-year-old striker stole in at the near post from Benjamin Angoua's right-wing cross to head past Ochoa.