Alena Sharp of Canada and Youngin Chun of South Korea shared the Marathon Classic lead at 7-under 64 on Thursday, a stroke ahead of Stacy Lewis and three others at Highland Meadows Golf Club. The 38-year-old Sharp, winless on the LPGA Tour, had eight birdies and a bogey. The 19-year-old Chun, also seeking her first LPGA Tour victory, had a bogey-free round. Lewis won the last of her 12 LPGA Tour titles in 2017. Azahara Munoz, Caroline Masson and Jenny Haglund matched Lewis at 65. Lexi Thompson was at 66 with U.S. Women's Open champion Jeongeun Lee6, Carlota Ciganda and Clariss Guce.