New Zealand held off a fierce Australian comeback to win a thrilling World Cup final and become the first team to retain their title.

Wonderful tries from Nehe Milner-Skudder and Ma'a Nonu had given the All Blacks a 21-3 lead early in the second half before David Pocock and Tevita Kuridrani struck back.

With 15 minutes to go there were just four points in it, but a nerveless long-distance drop-goal and penalty from Dan Carter snatched back control.

And when replacement Beauden Barrett sprinted away on to Ben Smith's clearing kick at the death history was made, with New Zealand also becoming the first three-time champions of the world.