Local teenage amateur Lydia Ko has held her nerve to clinch the New Zealand Women&aposs Open on Sunday. The 15-year-old fired a final round of four-under 68 at the Clearwater Golf Club to seal a one-stroke victory over American Amelia Lewis. The duo were tied for the lead with one hole remaining, but Lewis could only manage a bogey down the 18th to leave Ko needing just par to win the title. Ko&aposs tee shot finished in the rough, but she was good enough to find the green with her second and then needed just two putts to become the first New Zealand winner of the national women&aposs open. It was Ko&aposs third professional victory in just over a year, after having previously tasted success on the Australian tour at the New South Wales Open and the LPGA Tour&aposs Canadian Open. Australia&aposs Stacey Keating finished in sole possession of third place at eight under, two shots behind Ko, while Korean Seon Woo Bae was a further stroke adrift in fourth. Australian duo Sarah-Jane Smith and Nikki Campbell and England&aposs Elizabeth Bennett shared fifth place at minus six, while Italy&aposs Giulia Sergas was another shot back in eighth.