Lee was runner-up at last week's LPGA Thailand, going down to the last hole with eventual winner Amy Yang before finishing a shot short of a playoff.

Tied with Lee at four-under 68 were No.1-ranked Ariya Jutanugarn, Amy Olson, Yu Liu and Celine Boutier, who won her first LPGA tournament three weeks ago at the Vic Open.

World No.2 Sung Hyun Park bogeyed 18 after hitting her approach into a bunker for a 69 to drop into a seven-way tie for sixth, one stroke behind the leaders.

After an eagle on the 8th, her second-last hole, Olson just missed a 30-foot birdie putt on the 9th hole.

"I made a nice shot in, just perfect," the American said of her second shot into the 8th.

Scoring conditions on Sentosa Golf Club's Tanjong layout were difficult most of the day Thursday due to gusty winds and slick greens.

RIGHT: Defending champion Michelle Wie has withdrawn from the Women’s World Championship because of an ongoing wrist injury. PHOTO: Ross Kinnaird/Getty Images.

Former World No.1 Lydia Ko shot 72, as did Lexi Thompson and Cristie Kerr. Nelly Korda, who won the Women's Australian Open two weeks ago, had 74. Brooke Henderson dropped four shots in two holes on the 8th and 9th and had a 75.

Defending champion Michelle Wie was forced to withdraw with a recurrence of a right hand injury.

Wie, making her second start of the season after surgery on her right hand earlier this month, was 10-over after 14 holes when she withdrew while playing the 15th. She was holding her right wrist and hand as she walked up the fairway.

Wie fractured her hand and sustained extensive neck injuries in a car accident two years ago.

The original 63-player field has no cut. The top-12 players in the world went off in the final four groups on Thursday.

Yang pulled out with an undisclosed illness after three holes at three-over. Sei Young Kim also withdrew with a back injury after 12 holes.