American Ally McDonald earned a one-stroke lead after the opening round at the ANA Inspiration.
McDonald carded a four-under-par 68 on day one of the first major tournament of the LPGA Tour season.
The 26-year-old set the early pace in Rancho Mirage, California on Thursday – holing seven birdies to outweigh her three bogeys.
McDonald ended the round ahead of 2014 champion Lexi Thompson, world number five Ko Jin-young, Kim Hyo-joo and Linnea Strom at Mission Hills Country Club.
Lydia Ko – who won the tournament in 2016 – is two shots off the pace, alongside Lauren Stephenson, Lizette Salas, Jessica Korda, Cristie Kerr, Amy Yang, Jane Park, Lin Xiyu, Yan Jing and Lee Mi-hyang.
Meanwhile, defending champion Pernilla Lindberg posted a 73 to be one over heading into the second round.