Jane Park shot a bogey-free 6-under 66 to take the lead after the opening round of the Kia Classic on Thursday at Aviara.
Park had a one-stroke lead over Caroline Hedwall and Karrie Webb.
Stacy Lewis, playing her first round since taking over the world No. 1 ranking from Yani Tseng, was four shots off the lead after a round that she called frustrating. Lewis is trying to win her third straight tournament.
Tseng, the Kia Classic winner last year, was disqualified after oversleeping and missing her pro-am tee time Wednesday.
Park started on No. 10 and made the turn in 2 under. After a par on No. 1, she birdied four of the next five holes.