Demare and Stuyven had attacked from an elite chasing group, but only hit the front of the race inside the final 750 metres, bridging across to the front pair of Franck Bonnamour (B&B Hotels) and Stan Dewulf (AG2R Citroën).
Dewulf and Bonnamour had been out front by themselves for over 40 kilometres, attacking from a reduced peloton that had been split in the crosswinds. They looked on course to contest the title between them as they tackled the gravel sectors and short, steep climbs that punctuated the run into Tours.
But they were hunted down within the final kilometre as Démare and Stuyven themselves collaborated in the final ten kilometres, catching the pair within the final kilometre. Démare opened up his sprint first and sustained his power all the way to the line, with Bonnamour pipping Stuyven for the runner-up spot while Dewulf didn't contest the final dash to the line.
"I'm really happy, it's a lot of emotion," Démare said. "We know what I have been going through lately, no success, not the legs I wanted, today was a really ideal day. It was a sprint to the finish, I really didn't want to miss out.
"We stayed for a long time with Stuyven at 10 seconds behind the two riders, we were all in it together. Finally we get in, I take the initiative to close the gap. I threw everything I had into it and it worked. I'm very happy."
The introduction of the large amount of gravel and tough parcours to the final 50 kilometres of the 213 kilometre race has seen classics style racing and contenders more familiar over the cobbled parcours come to the fore, but Démare, best known as a sprinter, won this year's race.
"I didn't think that this new course of Paris-Tours would suit me but everything turned out as I wanted," Démare said.