Major championship winners Chun In-Gee of South Korea and Thailand's Ariya Jutanugarn shared the lead with three others atop a crowded first round leaderboard at the Bank of Hope Founders Cup.
Ariya, who won the 2016 British Women's Open, and 2015 US Women's Open champ Chun both shot eight-under 64 for a five-way tie for first with Americans Katie Burnett, Sandra Changkija and Stacy Lewis.
The 21-year-old Ariya delivered a bogey-free round that was highlighted by an eagle on the par-five 15th on the Desert Ridge Course.
"I feel pretty good because I tried to work on my commitment today and it's came out pretty good," said Ariya. "I missed a few putts, but I made two pretty long ones."
Chun, 22, has two majors on her resume as she also won the Evian Championship last year. She had nine birdies, including four in a row bridging the front and back nine.
The LPGA Tour players had to battle searing heat all day with temperatures reaching 32 Celsius (90F).
Lewis played with Ariya. She had an eye-popping front nine that was capped by a 136-yard hole-out eagle at the par four ninth.
"Nine was awesome," said Lewis, an 11-time winner on the LPGA tour. "The nine-iron was perfect in the air. It was nice to see it go in.
"If you tell me at the beginning of the day I would shoot eight under, and I'll take it any time."
Michelle Wie, hoping her game has been revitalized, shot a seven-under 65, to tie with Vicky Hurst, Julie Inkster, Jane Park and Sherman Santiwiwatthanaphong.
World number one Lydia Ko shot four-under. She also assisted playing partner Kim Sei-Young, who was stung on her right hand by a bee.
"After she hit her second shot on the 11th hole, she said 'Have you been stung by a bee before?'" said Ko.
Defending champion Kim was then treated by medical personnel before restarting her round.
Despite the bee sting, Kim fired a five-under 67.
"Sixty seven with a bee-sting is very impressive," Ko said.