Lille extends league winning streak
Maor Melikson had given mid-table Valenciennes a first-half lead, but Rudi Garcia's men slipped into another gear after the break, with goals from Ronny Rodelin, Tulio de Melo and Benoit Pedretti earning the three points.
The latter pair stepped off Lille's bench to make the difference, with Valenciennes unable to summon a response as the visitors - now fifth - closed in on the top three.
Dupraz had claimed that psychologically the game was "worth a thousand points", with Evian lying three points behind their opponents who occupied the last position above the drop zone.
By the time Cedric Barbosa and Saber Khelifa had scored twice apiece, Kevin Berigaud adding another to render Cedric Bakambu's 53rd-minute equaliser irrelevant, Evian had jumped two places to 16th and it was their shell-shocked opponents who were left residing in the bottom three.
Brest are still looking over their shoulder at the relegation places after losing 1-0 at home to Toulouse. Landry Chauvin's side headed into the game five points above the drop zone and looking to build on last weekend's 1-1 draw with title-chasing Lyon.
But Adrien Rabiot's goal on the stroke of half-time at the Stade Francis-Le Ble - coupled with Evian's win - saw Brest's margin over the bottom three shrink to just two points. Toulouse, meanwhile, climbed to 11th.
It was a dramatic night in the lower reaches and a woeful display from Reims goalkeeper Kossi Agassa helped Troyes lift themselves off the foot of the table and drag the away side ever closer to the drop zone after a 4-2 win.
Goals from Corentin Jean and Julien Faussurier put the home two in front with an hour gone before a late scoring spree, including Jean's second and a late effort from Mohamed Yattare added to the excitement.
Nicolas de Preville and Odair Fortes were on target for the visitors, making it 2-1 and then 3-2.