Australian Stephanie Kyriacou is two shots off the pace amid a congested leaderboard at the Evian Championship in Evians-les-Bains, France.
Boosted by an eagle two, the 23-year-old Sydneysider shot a five-under 66 to be in a five-way tie for 10th after the opening round of the fourth women's major of the year.
Patty Tavatanakit (Thailand), Gemma Dryburgh (Scotland) and Ingrid Lindblad (Sweden) each carded bogey-free rounds of 64 on Thursday to share the lead while there are six players at six under.
They include New Zealand's Lydia Ko, the 2015 winner.
American world No.1 Nelly Korda shot a two-under 69 and is tied for 21st with 16 others, including defending champion Celine Boutier of France and in-form Australian Gabriela Ruffels.
Australians Minjee Lee and Grace Kim opened with one-under 70s.
Hannah Green is two over while countrywomen Sarah Kemp and Hira Naveed need a good second round to survive the cut, being tied for 110th at four over.
Lee and Green will represent Australia in the women's tournament at the upcoming Paris Olympics.
"Today was good," said Kyriacou. "It was nice to get out early in no wind, the weather was a lot cooler.
"The round was quite boring. I would just hit it and hole a putt - boring is good sometimes."
That is except for the eagle on the par-four 12th.
"I had a wedge in, it was one bounce and went in," she said. "I didn't watch it, which is annoying but everyone cheered, and I was, 'that helps'."
Ruffels and Lee also holed out for eagles on a day of spectacular shot-making.
Kyriacou finished birdie-bogey-birdie, suggesting like so many rounds, it could have been better, but could have been worse.
Co-leader Lindblad is a former amateur world No.1 who only turned professional last month.
"I would say it's a pretty simple round of golf," she said.
"I think I missed two fairways, missed two greens, so was just in it the whole round. Was just trying to hit the targets that we have been talking about."
- with Reuters
