Lee, a 28-year-old American looking for her first Tour win, birdied four of her first five holes and, after a bogey at No.16, repeated the feat on her 7th.

She pieced together four straight birdies, and five in the next six holes, to reach eight-under at Superstition Mountain Golf Club before a bogey on her final hole dropped her into a three-way tie for top spot.

South Korea's Shin, 30, is looking for her first win since 2016. She posted seven birdies from holes eight through 18 to earn a share of the lead in the tour's first full-field event of the season.

Lopez had a bogey-free round. The 29-year-old Mexican started on the back nine and made the turn at four under par before adding three birdies on the front side.

Taiwan's Wei-Ling Hsu and England's Jodi Ewart Shadoff were tied for fourth after opening 66s.

Ten players are tied for sixth place at five-under, as 114 golfers in the 142-player field carded a score of even par or better.

Steph Kyriacou was the most successful Australian on day one, ending tied at 16th with a first round four-under 68.

Grace Kim was two shots further back on 70, in a tie for 48th, while Sarah Kemp shot 72, and Hannah Green and Karis Davidson each carded 73.

The event will debut the LPGA's new cut policy.

The cut after 36 holes will include the top-65 players and ties advancing to the weekend. Previously, the top-70 players and ties advanced to the final rounds.