Her round was an unusual mix of brilliance, recovery shots and mishaps but when the pressure ramped up, Ko responded and her nearest rival, England's Charley Hull, wilted.
That crucial swing came on the 12th when Ko birdied and Hull double bogeyed to fall five shots behind, the margin between the teenage pair when they started their final round.
Ko continued her steady progress, interrupted by one bogey on the 17th before she hit a superb iron to 10' on her final hole, grazing the cup with her birdie attempt.
Ko closed with a one-under 71 for her final round and a 14 under winning total of 202 to win by four shots from Australian amateur Hannah Green with Denmark's Nanna Koerstz Madsen third, a further shot behind.
Ko's victory was a measure of her class and endurance after taking out the Australian Open in Melbourne then crossing the Tasman to complete the double amidst all sorts of commercial and personal commitments around the NZ Open.
By Wynne Gray of the New Zealand Herald
