Bright start for Boutier boosts French hopes in Olympic women's golf
Treated to a rendition of the Marseillaise by excited French fans as she teed off, the world number seven and major winner kept her cool to notch up eight birdies and a lone bogey to post a seven-under-par round of 65.
"It was easy to be carried away by the emotions and all that, and it was nice to see so many people, but it's true that afterwards, I had to really focus," Boutier told reporters.
Boutier said her putting went as well as she could have wanted, with the pick of her scoring shots an 18-foot chip from off the green into the 16th hole to take her to seven under.
Playing alongside her, American world number two Lilia Vu revelled in the atmosphere and was pleased with a two-under-par clubhouse total that put her in tied-third place.
"This is really fun for me. I mean, they're cheering for me too, so I'm trying to keep up with Celine," she joked.
Boutier is seeking to outdo Victor Perez who thrilled French fans with a dazzling final round on Sunday to take fourth place in the men's competition.
The women's tournament will follow the same format as the men's contest won by American Scottie Scheffler, with 60 participants teeing off for a 72-hole, stroke-play contest over four days at Le Golf National.
Other early leaders included South Africa's Ashleigh Buhai, second at four under, and Colombia's Mariajo Uribe, who will retire after the Paris Games, part of a four-way tie for third place at two under.
Tokyo gold medallist Nelly Korda, the world number one, shot a level-par round of 72 after recovering from three early bogies, with the American, like others, saying the greens were tricky to read.
"Overall, it just took a little bit to adjust but I adjusted well on the back nine," Korda said.
Britain's Charley Hull was near the bottom of the leaderboard with a nine-over-par round.
The world number 11 put her performance down to rustiness after a shoulder injury, brushing off the idea that an Olympic ban on smoking had disadvantaged the player known for puffing on courses.
Perrine Delacour, France's other representative, said the emotion of hitting the first tee shot of the competition drained her and contributed to a disappointing seven-over par.