Canadian Brooke Henderson birdied five of her last eight holes for a 6-under 65 that gives her a share of the lead with Eun-Hee Ji in the season-opening Diamond Resorts Tournament of Champions on the LPGA Tour.
The 26-player field is for LPGA winners from each of the last two seasons.
Ariya Jutanugarn, the world's No. 1 player who captured every major award last year, opened with a 67.
In men's golf, Phil Mickelson will try and build off one of the best rounds of his career at the P-G-A's Desert Classic in La Quinta, California.
Mickelson began his 27th full season as a pro by firing his 12-under 60 in first-round play.