The South Korean duo were tied for the lead with one hole remaining but Choi surged ahead at the par-five 18th when she hit a second-shot three wood to 45 feet from the hole and made the putt for a dramatic finish to her round.
"I got the three wood out first, then changed it to a pitching wedge and then back to three wood because there is a small gap to the right side of the green," Choi said.
"The wind helped me a lot, (it) was a little bit helping right to left, so I just hit three wood.
Last year's champion Stacy Lewis, who shot a 65, American Brittany Lincicome, Japan's Mika Miyazato and South Korean Amy Yang are tied for fourth on nine under.
Rain on Friday forced 63 players in the field to complete their first rounds on Saturday.
(Editing by Greg Stutchbury)
Share
