Lydia Ko: World number one wins New Zealand Open

Ko became the youngest winner of the LPGA Tour when she won the 2012 Canadian Open, aged 15

Teenage world number one Lydia Ko won the New Zealand Open by four shots.

The 17-year-old New Zealander, who also won last week's Australian Open, hit a one-under-par 71 to finish on 14 under.

Australian amateur Hannah Green equalled the lowest round of the day at Christchurch's Clearwater Golf Club with, a four-under 68 to finish second.

England's Charley Hull, who started the day three shots behind Ko, eagled the 10th but played the last eight holes in five over and dropped to tied sixth.

Hull, 19, had closed to within two shots after the 10th but she double-bogeyed the par-four 12th and had further dropped shots on the 15th, 17th and 18th as her challenge faded.

Ko, who won this event as an amateur two years ago, birdied the opening two holes of her round and knocked in another on the sixth to extend her overnight lead.

However, a double bogey on the par-four eighth, followed by a bogey on the ninth, threatened to derail her round but Ko steadied herself with birdies on the 10th and 12th holes.

"This is even better than I would ever have imagined," said Ko, who carded a course record 61 in the second round.

"It's just great to have won the two Opens back to back."