The defending champion had a 10-under 132 total, to lead by two strokes under a burning sun, but the heavens opened up moments after she signed in her card.
"Gangnam Style is the most famous Korean product now, but I am not good at it, and have tried it only in private," said the World No 4.
Second is Sydnee Michaels from the United States, who is two strokes adrift after a six-under 65 for a eight-under 134 total.
Bunched third on seven-under 135 are Suzann Pettersen of Norway, Lizette Salas of United States, Momoko Ueda and Mika Miyazato of Japan.
"I simply love Malaysia and this golf course as I know it well, but still, the back nine is quite difficult to tame and that is why I had bogies on the 11th and 17th.
"To win the tournament, I need to be more careful on the 17th, which I think is the trickiest for me. There are many players out there who can do six and seven-unders per-day and with two more rounds, nobody knows what is going to happen," said Choi.
She left her parents back home this time, but has her weight trainer and English tutor for company.
"My English is not that good, so I watch many American TV series and also have my personal tutor who came with me to Malaysia. I did weight training Monday and Tuesday, and feel simply great now," exclaimed the charming Korean.
As for joint-third Suzann, the birdies sang more often for her today than in her opening par-round.
"Seven birdies and a bogey free round as compare to my par on Thursday was simply amazing. I had a lot of easy birdies (first, eighth, 10th, 14th, 15th, 18th, 18th) which pulled me up from tied-39th to tied-third.
"So I can't complain about this solid round," said Suzann.
A hole-in-one was hit by Lizette on the par-three 15th, which saved her three straight bogies on the 10th, 11th, and 12th. She moved up from joint-eighth to be in contention going into the third round today.
"I had a 130 to Number 15, and hit a good swing and it just rolled in. It erased two bogies to move me up," said Lizette.
World No 1 Yani Tseng played one-over 72, but her disastrous opening 78 has placed her joint 61st on eight-over 150.
