Les Bleus had deservedly gone into the interval comfortably ahead thanks to Louis Picamoles and Yoann Huget tries, while Camille Lopez also kicked a penalty and drop-goal, but they were awful after the break.
Jacques Brunel’s men failed to maintain their authority on proceedings and Warren Gatland’s outfit got themselves back into the contest via Tomos Williams and North.
Going into the final quarter, the French were just two points in front but Wales had the momentum and Dan Biggar gave them the lead.
Although Lopez restored the hosts’ buffer, North had the final say to give Wales a winning start to the tournament and set them up nicely for the rest of the competition.
The 2012 and ‘13 winners endured a dreadful start, however. There had been plenty of positivity within the country going into this tournament but it was the hosts who were sprightly early on. On his return to the team, Damian Penaud impressed while their big pack consistently got over the gain line.
They were creating space in the wide channels and it was no surprise to see the home team touch down first as Maxime Medard fed Picamoles and the number eight duly powered over.
It was a brilliant start from the French but they should have been pegged back when Liam Williams took an outstanding line and appeared to have scored.
The full-back, despite the difficult conditions, should have finished but the Saracens man knocked on and that was to prove costly with Les Bleus continuing to cause problems for the Welsh defence.
North was the one to succumb, poorly deciding to come inside and allowing Huget to sprint clear. It was a brilliant offload from the impressive Arthur Iturria but the wing’s error was rather symptomatic of the visitors’ first-half performance.
Mistakes were prevalent and France pounced, opening their buffer further through Lopez’s penalty and well-taken drop-goal.
The early exchanges of the second period seemed to be heading the same way, with the match being peppered by errors from Gatland’s outfit, but a piece of individual brilliance from Josh Adams got the visitors back into the contest.
Adams spotted some space in the centre of a ruck and scythed through before finding the supporting Williams, who had the simple task of finishing the chance.
That altered the momentum and all of a sudden it was Brunel’s charges that were under duress. Huget ceded and, ironically, it was North who benefited. Roles were very much reversed as the Frenchman failed to deal with a grubber through and the British and Irish Lion was on hand to excellently pick up and score.
Gareth Anscombe, who had endured a poor day with the boot, kicked a second conversion before Biggar came on to the field to incredibly move Wales ahead.
Moving into the final 10 minutes, the visitors held a one-point advantage but, after being sent into reverse at a scrum, Lopez regained France’s lead.
However, the hosts then proceeded to press the self-destruct button as Sebastien Vahaamahina threw a shocking pass, which North intercepted and finished to snatch a remarkable win.
Tries: Picamoles, Huget
Pens: Lopez 2
Tries: T Williams, North 2
Cons: Anscombe 2, Biggar
France: 15 Maxime Medard, 14 Damian Penaud, 13 Romain Ntamack, 12 Wesley Fofana, 11 Yoann Huget, 10 Camille Lopez, 9 Morgan Parra, 8 Louis Picamoles, 7 Arthur Iturria, 6 Wenceslas Lauret, 5 Paul Willemse, 4 Sebastien Vahaamahina, 3 Uini Atonio, 2 Guilhem Guirado (c), 1 Jefferson Poirot
Replacements: 16 Julien Marchand, 17 Dany Priso, 18 Demba Bamba, 19 Felix Lambey, 20 Greg Alldritt, 21 Baptiste Serin, 22 Gael Fickou, 23 Geoffrey Doumayrou
Wales: 15 Liam Williams, 14 George North, 13 Jonathan Davies, 12 Hadleigh Parkes, 11 Josh Adams, 10 Gareth Anscombe, 9 Tomos Williams, 8 Ross Moriarty, 7 Justin Tipuric, 6 Josh Navidi, 5 Alun Wyn Jones (c), 4 Adam Beard, 3 Tomas Francis, 2 Ken Owens, 1 Rob Evans
Replacements: 16 Elliot Dee, 17 Wyn Jones, 18 Samson Lee, 19 Cory Hill, 20 Aaron Wainwright, 21 Gareth Davies, 22 Dan Biggar, 23 Owen Watkin
Referee: Wayne Barnes (England)
Assistant referees: Andrew Brace (Ireland), Brendon Pickerill (New Zealand)
TMO: Rowan Kitt (England)
by Colin Newboult