CARLSBAD, California, March 21, 2013 (AFP) - Park played without a bogey, but she had some big names in striking distance.
Hall of Famer Karrie Webb of Australia had six birdies and one bogey in her five-under 67, which had her tied for second alongside Sweden's Caroline Hedwall.
Italian Giulia Sergas and American Jessica Korda were tied for fourth on 68, while the 10 players tied on three-under 69 included South Korean Hall of Famer Se Ri Pak and US star Paula Creamer.
Park started on the back nine and birdied 13 and 17. After another birdie at the second, she birdied three in a row from the fourth.
"The golf courses here just really fit my eye," Park said. "I just love this style of golf course, so maybe that's why I played pretty well today."
Webb powered her way into contention with four birdies in a five-hole stretch. She birdied the fourth, and after failing to take advantage of the par-five fifth she birdied three in a row from the sixth.
Birdies at 12 and 14 sandwiched her lone bogey of the day at 13.
"Tee to green was pretty solid," she said. "I only missed a couple fairways, a couple greens and made some putts, which is good in the afternoon on these poa annua greens, so it was a pretty solid round.
"I didn't really get myself in too much trouble, just one hole I missed a fairway and was in the deep rough, but other than that it was all right."
Hedwall grabbed her share of second place despite a double-bogey on the par-five 10th -- where she put two balls in the water.
She countered that and one bogey with eight birdies, six of them on the front nine.
The tournament is without defending champion Yani Tseng, who was toppled from the No. 1 spot in the world rankings this week by America's Stacy Lewis.
Tseng overslept on Wednesday and missed the tee time for her pro-am round. Under LPGA rules, failing to appear for the pro-am bars a player from competing in the tournament.
An embarrassed Tseng issued a statement on Wednesday saying she overslept.
"I was extremely excited to compete this week to defend my title at the Kia Classic and to try to regain the No. 1 spot," she said. "This was an unfortunate mistake and I want to apologize to Kia, my sponsors and all of the fans. I can't wait to come back here next year."
Lewis, making her first start as the world No. 1, carded a two-under 70 that left her tied for 16th.
Leading first-round scores on Thursday in the LPGA Kia Classic (USA unless noted):
66 - Jane Park
67 - Caroline Hedwall (SWE), Karrie Webb (AUS)
68 - Giulia Sergas (ITA), Jessica Korda
69 - Amanda Blumenherst, Lizette Salas, Se Ri Pak (KOR), Austin Ernst, Jodi Ewart Shadoff (ENG), Inbee Park (KOR), Beatriz Recari (ESP), Paula Creamer, Haeji Kang (KOR), Mo Martin
70 - Carlota Ciganda (ESP), Jenny Shin (KOR), Maude-Aimee Leblanc (CAN), Jacqui Concolino, So Yeon Ryu (KOR), Sandra Gal (GER), Cristie Kerr, Stacy Lewis, Belen Mozo (ESP), Kristy McPherson