Australia's Minjee Lee has lived up to her pre-tournament billing by sharing the lead after her opening round of the year's first women's golf major in California.

Lee and American Jennifer Kupcho posted 6-under-par 66s in benign morning conditions at the Mission Hills Country Club in Rancho Mirage to lead by one shot from defending champion Patty Tavatanakit of Thailand.

Australian rookie Gabriela Ruffels was in a six-way tie for fourth place, alongside the likes of New Zealand's former world number one Lydia Ko, after shooting a 4-under 68.

Fellow Australian Hannah Green was also well placed after a steady 2-under 70 to be tied for 16.

Up to fourth in the world rankings following a solid start to 2022, Lee was among the favourites at a course very much to the pure ball-striker's liking, and she duly delivered with six birdies in a bogey-free round.

The 25-year-old birdied all four par-fives in the sunny and calm conditions to earn herself a jump on the field.

"It was perfect," Lee said.

"Not like a breath of wind when we played. Maybe just a tiny bit, but conditions are great. Putting greens are rolling real nice.

Lee won her first major last year with victory at the Evian Championship in France.

"I know I have one [major] under my belt, but I do want a little bit more," she said.

"I just think I have a little bit more belief in myself and my game so I can be a little bit more comfortable just hitting the shots that I choose."

Kupcho birdied holes 11 through to 14 to get to 8-under, then bogeyed the next two holes. She birdied four of the first five holes and finished with nine birdies and three bogeys.

AP/ABC