(Reuters) - World number one Lydia Ko surged into a share of the halfway lead with a five-under-par 66 in the second round at the Marathon Classic in Sylvania, Ohio on Friday.
Ko gathered six birdies in a testing breeze on the Highland Meadows course to join South Korean Kim Hyo-joo (68) at eight-under 134, one stroke ahead of American Alison Lee and South Korean Jang Ha-na, with Ariya Jutanugarn of Thailand among a trio two shots back.
American Brittany Lang, winner of the U.S. Women's Open on Sunday, shot 69 to trail by five strokes.