Updated

South Koreans In Gee Chun and Sung Hyun Park birdied eight holes each as they carded 8-under rounds of 63 for a share of the lead in the first round of the Evian Championship on Thursday.

In the fifth and final major of the season, New Zealander Lydia Ko's bid to defend her title — and clinch a third career major by the age of 19 — got off to a rocky start as she finished seven shots behind the co-leaders.

While Ko's play was patchy, with a bogey and only two birdies, her rival Ariya Jutanugarn of Thailand had a day to forget with a 2-over 73 featuring a triple bogey.

Ko and Ariya have a good chance at the Evian of taking the Annika Major Award, which rewards the major winner with the best combined record at all five majors of the season, and is named after 10-time major winner Annika Sorenstam.

A win here would clinch the award for either Ko or Ariya, but they face an uphill struggle.

Ko revealed herself to the golfing world at the Evian in 2013, when she finished second as a 16-year-old amateur.

This year, another young player emerged into contention on her tournament debut.

American Annie Park posted an eagle and five birdies in a 7-under round of 64 to move into a tie for third place with Olympic bronze medalist Shanshan Feng, who was third here last year. They are one stroke behind the leaders.

Annie Park's performance caught the eye; and not least because her mum was caddying for her.

Ranked 201 after turning professional this year, Annie Park showed good composure in overcast and somewhat drizzly weather conditions on the picturesque course perched over Lake Geneva.

She enjoyed a run of birdie-birdie-eagle on her front nine, then started and finished with birdies on the back nine.

American Angela Stanford posted a 6-under 65 to move into fifth, one shot ahead of South Koreans So Yeon Ryu and Eun-Hee Ji.