Choi has 2-stroke lead in LPGA Malaysia

South Korean golfer Na Yeon Choi holds a two-stroke lead at the halfway stage of the LPGA Malaysia. (AAP)

South Korean golfer Na Yeon Choi holds a two-stroke lead at the halfway stage of the LPGA Malaysia. (AAP)

Korean Na-yeon Choi has a two-stroke lead in the Malaysian LPGA event but joint first-round leader Karrie Webb has fallen four strokes behind.

Defending champion Na-yeon Choi of South Korea shot a four-under 67 on Friday to take a two-stroke lead at the halfway stage of the LPGA Malaysia.

But joint overnight leader Karrie Webb could manage only even par 71 and dropped to a tie for seventh in a group including fellow Australian Lindsey Wright (66), four strokes off the pace.

The 25-year-old Choi moved to a total of 10-under 132 at Kuala Lumpur Golf and Country Club.

LPGA Tour rookie Sydnee Michaels was second on eight-under after a second-round 65.

Suzann Pettersen of Norway, who started the day in a tie for 39th, produced the day's best of a 64 to make her move to one stroke behind Michaels at 7-under along with three others: Japanese Momoko Ueda (67) and Mika Miyazato (69) plus American Lizette Salas (67), who had a hole-in-one on the par-three 15th.

Choi won the US Women's Open in July for her first major title and is chasing her seventh win on the LPGA Tour.

"I struggled on the back nine, dropped two shots but I expected that," she said.

"Back nine is much harder than front."

The tournament opens the American tour's four-event Asian swing.