Rasmus Højgaard equalled the course record at Le Golf National after firing ten birdies in his first-round 62 to lead the 2022 Cazoo Open de France by two shots.
The three-time DP World Tour winner carded six birdies and a solitary bogey on the front side before picking up four more shots on the homeward nine to get to nine under par.
Højgaard's stunning opening round at the 2018 Ryder Cup venue featured several highlights, including a monster birdie putt from more than 70 feet and a tee-shot that was six inches away from a hole-in-one.
Swede Alexander Björk was alone in second on seven under after notching seven birdies in his bogey-free 64.
Paul Barjon was another shot back in third after the morning starter signed for a 65 to finish the day as the leading Frenchman as continental Europe's oldest national open returned for the first time since 2019 after the Covid-19 pandemic meant it was not played in 2020 and 2021.
Højgaard opened his first round with a birdie, rolling in a ten-footer from just on the green before giving the shot straight back at the second.
He recovered from that bogey in style, taking advantage of the long third before holing from 72 feet for an unlikely birdie at the fourth.
The Dane made it three gains in a row on the fifth courtesy of a delightful approach to four feet from the first cut of rough.
Højgaard's impressive form on the greens continued as he sank his 15-foot birdie attempt at the seventh before pulling off a good up-and-down for par on the eighth.
After closing his front nine with another birdie at the ninth, Højgaard came within inches of holing his tee-shot at the short 11th for an ace but instead had to settle for a tap-in birdie.
He produced another good par save after missing the 12th green before taking the outright lead on seven under with a 19-foot birdie putt at the 13th.
Another birdie on the next hole moved the 21-year-old to eight under, and while he gave himself further chances on the 16th and 17th, he had to make do with pars there.
And after sending his approach to 21 feet at the 18th, he confidently curled in the birdie putt to head into the clubhouse with a two-shot lead.
He said: "Today was very good.
"To be fair, I don't feel like I was that good off the tee but my approach play was very good today, alongside a very good putter.
"I holed a few long putts out there but you have to do that to shoot nine under.
"It's quite cool to have a course where you need to think your way round a bit. That's what this course gives you.
"It tests you in all parts of your game."
Björk birdied the third and seventh before holing his chip shot for another gain at the eighth.
He then picked up four more shots on the back nine thanks to some superb putting.
Björk said: "It felt really good. I've not had too many of these rounds this season so far so it was a lot of fun to have the feeling again that you can actually hit the ball where you want and hole a few putts as well.
"I was in very good control of my feelings today so it was nice."
French amateur Martin Couvra was among the large group in a tie for fourth on five under after his opening 66.