The reigning LPGA rookie of the year, 23, carded a two-under par 70 to finish on 10 under for the tournament, with compatriot Lee Mi-hyang on seven under.

Ko is the 15th woman from South Korea to win a major and the fifth to win the tournament.

American Lexi Thompson was third on six under, while England's Charley Hull was 12th on three under.

Ko's victory followed her win two weeks ago at the Bank of Hope Founders Cup and her recent form is set to move her top of the world rankings.

She was in tears as she putted a birdie on the 18th and celebrated by jumping into Poppie's Pond at the Mission Hills Country Club.

"I always think about when I can go in that pond," she said. "That's today."

"I had a great round and a great week. I felt nervous today but I just tried to keep myself calm. My caddie told me on the 18th that I had a two-shot lead and to not worry, just enjoy it."

Ko, who was second at the British Open in 2015, added: "I won the tournament and that's a happy moment. I thank God, I thank my parents, I thank my grandparents. It is an honour for me to join so many great Korean players."

England's Jodi Ewart Shadoff finished on two over with compatriot Georgia Hall on five over. World number one Park Sung-hyun tied for 52nd on four over.