overcame a five-shot deficit in the final round to claim victory at the LPGA's Lotte Championship in Hawaii on Saturday.
The 19-year-old played her final eight holes in six-under-par, chipping in for an eagle-three at 13 on the way to a bogey-free eight-under 64.
Lee's combined 16-under was one better than South Korea's Chun In-gee (67) and overnight leader Katie Burnett (70), whose title hopes were dented by a three-putt bogey at 16.
Lee said her coach had reassured her the title was still up for grabs despite starting the day five shots back.