Yuka Saso had a roller-coaster round of one-over-par 73 to slip to joint 36th halfway through the BMW Ladies Championship at the Oak Valley Country Club in South Korea Friday.

The 20-year-old Filipino-Japanese birdied the second hole for the second straight day but made seven bogeys against three birdies through the next 11 holes.

An eagle on the par-5 15th hole stopped the bleeding as Saso closed with three straight pars to bring her 36-hole total to 1-under 143.

Averaging 273 yards off the tee, Saso hit eight of 14 fairways and 12 of 18 greens but needed 32 putts.

Korean American Andrea Lee grabbed the second-round lead with her second consecutive bogey-free 66 to reach 12-under.

Two shots behind were world No. 2 Atthaya Thitikul, South Korean amateur Kim Min-sol and Lilia Vu of the United States.

Lee said a victory in South Korea would mean so much.

"Just to be here and to play in Korea for the first time means a lot. And if I were to be able to cap it off with the win, it would be even more special," she said.

Lee made two birdies in the front nine and four birdies coming home.

"Really solid, another bogey-free round, which I'm really pleased with," Lee said. "I just made some putts out there. Hopefully, I can keep it going on this weekend."

Thitikul, the overnight leader, had a roller coaster ride through the back nine.

She missed a couple of makeable birdie attempts on 5 and 6, before finally getting her first birdie on 8.

She bogeyed 12, found trouble off the tee at the 13th and missed the green to right. After a chip, she missed her par attempt and then bungled a bogey to drop to seven-under.

Thitikul birdied the very next hole and then eagled the par-five 15th to salvage a round of 71.

Kim Min-sol, one of two South Korean amateurs here this week, made three birdies, one eagle and three bogeys for a 70.

Yoo Hyun-jo, the other Korean amateur, also had an eagle en route to a 68. She is at four-under for the tournament.