Jennifer Kupcho of the United States fired a bogey-free 7-under 65 to share the lead alongside four other golfers after the opening round of the LPGA Thailand on Thursday.
The crowded leaderboard was no surprise on the Pattaya Old Course: The average winning score over the past 10 years is 21 under par.
Kupcho's round was highlighted by a birdie-birdie finish and an eagle on the par-5 10th hole at Siam Country Club. With her in the lead were 2014 champion Anna Nordquist of Sweden, six-time USLPGA Tour winner Nasa Hataoko of Japan, local hope and tour rookie Jaravee Boonchant, and last year's runner-up, Lin Xiyu of China.
Brooke Henderson of Smiths Falls, Ont., is four shots back of the leaders and tied for 28th after firing an opening-round 69.