Lille overturned a one-goal deficit at the Stade du Hainaut tonight to extend their Ligue 1 winning streak to five matches and win the battle of the north of France in the process.
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.
They are three points shy of third-placed Marseille, albeit having played a game more, but an assault on a Champions League place is not beyond them.
In this form, it looks a certainty, and they were excellent throughout tonight, letting their guard down just once.
They were quick out of the traps with Dimitri Payet working Nicolas Penneteau from distance, the goalkeeper then doing well to block Salomon Kalou after smart work from Rodelin.
Kalou then played in Payet who got through on Penneteau and was denied by him twice - the keeper wondering what sort of a night he was in for.
A busy one was the answer and he was soon rebuffing a Kalou volley before, with 25 minutes gone, his hard work was validated when Melikson broke into the area and beat Steeve Elana from 12 yards.
VA held that lead until the break but, 10 minutes after the restart, an equaliser arrived, with Rodelin unmarked and beating Penneteau with a header from Marvin Martin's cross.
It was harsh on Penneteau that his work had failed to keep a clean sheet and despair set in when a second Lille goal, after endless probing, arrived.
Eight minutes remained when it came, De Melo following Rodelin's example and rising to nod in after a Divock Origi centre.
The scoreline was then given a more realistic look as Lille made it three with seconds remaining, Pedretti getting the ball after a poor clearance and lobbing an unfortunate Penneteau.