But even better was to come at the last, and it has put Korda in a very strong position heading into the weekend - 16 under par and four shots clear of her nearest competitor.
She began the day at three-under and in a tie for 16th but now sits back in a tie for 32nd at -1.
After a somewhat uneven start with two birdies and a bogey, Korda sank four birdies on the back nine including a 25-footer on the 17th hole to finish with a five-under-par 67. She would have gotten there but for that two-shot penalty she incurred after improperly removing signage on Friday, since LPGA.com projected Thompson needed a solo second and a fifth-place finish or worse for now top-ranked Shanshan Feng. "This was my first event my rookie year". If she can continue her solid play and avoid more flukey penalties, she should have a good chance to pick up her first win of 2018. "There is a lot of support and it feels nice having people cheering you on".
"I felt at one point I was in the trees on nine and hit a punch out into the bunker and I felt like Tiger Woods", Korda said.
Korda explained that recent surgery on her jaw has helped relieve the constant pain she was under.
World No.8 Ariya, a runner-up in 2013, started off with an eagle at the par-five first hole.
"It's a second-shot golf course".
"It was great fun playing with Pornanong [Phatlum] and playing in front of all the Thai fans", said world No.8 Ariya.
She's trying to become the first Thai victor of the tournament.
Thompson, who won this event in 2016 by six shots with a 20-under total and tied for fourth previous year, started her latest round in style with an eagle followed by a birdie only to bogey the third hole.
Korda's own sister Nelly finished in a tie for 14th.
A frustrating second round for Lydia Ko has her lying a long way behind the leaders two rounds into LPGA Thailand.
Play was suspended due to lightning at 4.31pm with the final group on the 18th tee.