Major winner Kim Sei-young in three-way lead at LPGA Thailand
Also at 10-under after two rounds at Siam Country Club Pattaya were Sweden's Madelene Sagstrom and homegrown talent Patty Tavatanakit.
Three more players were tied for fourth - Switzerland's Albane Valenzuela, Thailand's Jaravee Boonchant and the Korean world number nine Kim Hyo-joo.
Together with home hope Ariya Jutanugarn, who was in a tie for 10th, Valenzuela fired the lowest round of the day with her seven-under-par 65.
World number one Lilia Vu, the defending champion from the United States, carded a 67 to go with her opening-round 73 and is tied 30th.
Co-leader Kim won the Women's PGA Championship in 2020 and is chasing a 13th LPGA title.
The 31-year-old Korean carded a 68 that was sprinkled with four birdies and an eagle, before two bogeys took the shine off her round.
"Last three holes I wasn't good, so a little bit disappointed with that. But I played quite solid the front nine," said Kim, who shot an opening-round 66.
"I feel like the key is how to play more relaxed on the course."
Sagstrom, ranked 65th in the world, managed five birdies in her front nine to finish with a five-under 67 for the second day running.
"I'm happy that I kept it together in the end," Sagstrom said.
"Obviously would've liked another two birdies in the back nine, but I started so solid, so I can't complain."
The windy conditions gave some players trouble in the afternoon with Thursday's leader, Taiwan's Chien Peiyun, carding a 72 to go with her opening 64.
