Kane Williamson coolly struck a straight six to give New Zealand a one wicket victory over Australia in a dramatic battle between the cricket World Cup hosts at Eden Park.
Williamson lofted Pat Cummins over the boundary with last man Trent Boult at the wicket to finish on 45 not out in New Zealand's 152 for nine off 23.1 overs.
Mitchell Starc scythed through the New Zealand batting after Brendon McCullum had given the home side a flying start with 50 from 24 balls, including seven boundaries and three sixes, to take six for 28 from nine overs.
Earlier, New Zealand's left-arm fast bowler Trent Boult recorded his best figures in an ODI, capturing five wickets for one run during his second spell, to finish with five for 27 in Australia's 151 all out from 32.2 overs.
There was no hint of what was to follow at the start of the day when Australia, who won the toss, set off as if they were determined to post a total around the 400 mark.
Tim Southee conceded 15 runs off the first over of the day, David Warner slashed a six off his second over the short third man boundary and Aaron Finch struck the pace bowler over mid-on into the stands off the third.
With his next ball Southee knocked Finch's off stump out of the ground after he had scored 14.
Australia failed to recover after that and it was only Brad Haddin's quickfire 43 that took them past the 150-run mark.
Australia 151 all out in 32.2 overs (Haddin 43, Boult 5-27)
New Zealand 152-9 in 23.1 overs (McCullum 50, Starc 6-28)