Richard Gasquet and Pierre-Hugues Herbert left France on the cusp of a first Davis Cup victory since 2001 after winning a keenly fought doubles rubber against Belgium in Lille.
A win apiece for Belgium's David Goffin and France's Jo-Wilfried Tsonga left the final nicely poised at 1-1 after Friday's singles encounters.
And it was the host nation, runners-up in 2014, that stole a march as Gasquet and Herbert defeated Joris De Loore and Ruben Bemelmans 6-1 3-6 7-6 (7-2) 6-4.
France made a lightning start, Herbert's quick reactions at the net helping to make the initial break that quickly became a 4-0 lead from which Belgium could not recover.
However, after some words of encouragement from captain Johan Van Herck, the momentum swung Belgium's way.
France recovered from going 3-1 down to break back thanks largely to wonderful lob from Herbert, but Belgium broke again for a 4-2 lead that proved crucial in the second set.
It looked as though Belgium would press home the advantage, Herbert taking a stinging forehand flush on the forehead as France slipped 3-1 down.
But there was a deafening roar as France levelled once again at 5-5 before dominating when the set reached a tie-break.
There was little given up from either team at the beginning of a tense fourth, but Belgium squandered two break points in game six.
France duly took full advantage as some great work from Gasquet's forehand helped the hosts to earn a crucial break in the next game, with Belgium unable to mount a comeback.
If Tsonga can now beat Goffin in the first rubber of Sunday's action, then France will win a 10th Davis Cup title and draw level with Great Britain in third on the all-time list of champions.
