Leona Maguire is 10 shots off the lead after the opening round at the Portland Classic, well adrift of early leader Ayako Uehara of Japan, who fired a seven-under-par 65.
A three-over 75 at the Columbia Edgewater Country Club left the Cavan native in a tie for 102nd and in danger of missing the cut.
Maguire birdied the eighth but four bogeys means she has work to do to make her way back inside the projected mark which stood at level par after the opening round.
At the top of the leaderboard, however, Uehara rolled in eight birdies and recorded just one bogey to take a one-shot lead over Australia's Hannah Green, who shot a six-under 66.
World number two Nelly Korda opened with a five-under 67 to join a tie for third with Caroline Inglis and Japan's Ayaka Furue and Hinako Shibuno.
Uehara both started and finished her round strongly. She made five birdies on the front nine and three more over her final four holes, including 17 and 18.
The 38-year-old has won three times in Japan but is seeking her first LPGA Tour victory. She said being out front will not affect how she approaches the second round.
"I don't think so," Uehara said. "I will do just my game and then focus one at a time."
Evian Championship winner Brooke Henderson of Canada opened with a four-under 68. She was tied for seventh with countrywoman Alena Sharp, Lilia Vu, Anne van Damof the Netherlands, Jenny Shin of South Korea and Tiffany Chan of Hong Kong.
Defending champion Jin Young Ko of South Korea, the number one player in the world, withdrew from the event earlier this week to rest a wrist injury.
Additional reporting: Reuters