Australian Katherine Hull made a handy start to the LPGA Championship, shooting a two-under 70 to trail leader Yani Tseng by four shots.
Hull highlighted her round with an eagle on the par-5 17th as she finished her first round in a group tied for 13th spot at Locust Hills in Pittsford, New York on Thursday.
World No.1 Tseng shot a 66 to take a one-stroke lead over American Paula Creamer in the second women's major championship of the year.
Australia's Sarah Jane Smith shot a 71 while countrywomen Karrie Webb and Sarah Kemp have work to do after battling to 74s.
Defending champion Cristie Kerr, who was ailing with a light case of the flu, shot an even-par 72.
Play was halted in the early evening by a severe thunderstorm with 58 players still on the course.
Taiwan's Tseng made five birdies on the front nine and three more on the back to go with a pair of bogeys.
She recovered from a bad tee shot at the par-4 18th hole that landed in the thick right rough, hit her second shot to four feet, and drained the birdie putt for sole possession of the lead.
