Lucas Bjerregaard will take a one-shot lead into the second round at the 100th Open de France but he will have defending champion Bernd Wiesberger hot on his heels at Le Golf National.
The Dane had made just three of his last ten cuts but he found his form on the biggest stage with an elite field gathered at the course where the Ryder Cup will be held in 2018.
He made the 26th hole-in-one of the season on the second as he signed for a five under par 66 and would not be caught on a day of sun and occasional showers in Paris.
But while he goes in search of a first European Tour title, Wiesberger, Thongchai Jaidee and Thomas Pieters - who all sat just a shot back - have 12 between them.
Bjerregaard was playing with totally new clubs after his were lost in transit but he showed no ill-effects as he holed from 202 yards with a seven iron on the second.
He followed that with three birdies and a bogey in the next four holes and came home in 34.
"It's a great start and I think that's what I've been needing these last few past weeks," he said. "I've been playing decent and seeing a lot of improvements. I just haven't really put any good rounds together.
I got a little momentum off that hole-in-one there and it was nice to back it up on the holes after and nice to shoot a good number today - Lucas Bjerregaard
Wiesberger opened with three birdies in his first four holes and the Austrian added further gains on the 15th and 16th with a single bogey on the eighth.
"You never know how it's going to turn out the following year, but every time I come back here, I enjoy playing this place," he said. "I was doing the right things today, hitting good tee shots and got myself into position, and that's the key around here.
"All aspects of the game were quite good today and therefore I'm pretty pleased with the round. It wasn't easy, we had a bit of rain and the wind was up. But I felt comfortable.
I stepped over the ball and I felt like I knew what it's going to do on any club and therefore I'm pretty pleased with my first round - Bernd Wiesberger
Belgian Pieters had set the clubhouse target early as he recorded five birdies and a bogey and Jaidee joined him at four under late in the day as he recorded an eagle, four birdies and two bogeys.
Spaniard Adrian Otaegui was also at four under after recording the only bogey-free round of the day with birdies on the 12th, second, third and ninth.
The Molinari brothers - Italians Edoardo and Francesco - were then at three under alongside England's Chris Hanson and local favourite Mathieu Decottignies-Lafon.
There was then a group of eight players at two under with World Number Four Rory McIlroy level par and Masters Tournament winner Danny Willett four shots further back.
