New Zealand survived a late collapse to beat Australia by one wicket in a thrilling World Cup Pool A game on Saturday.
Chasing a meagre 152 to win, the Kiwis slipped from 131-4 to 146-9 as Mitchell Starc claimed 6-28.
However, Kane Williamson (45no) hit Pat Cummins for six to seal victory with 26.5 overs to spare in a wonderfully tense climax at Eden Park in Auckland.
Earlier, Australia lost eight wickets for 26 runs as they were bowled out for 151, with Trent Boult claiming 5-27.
“I was always going to try and hit a boundary at the end as I didn’t want to leave it too long,” Williamson told Test Match Special.
New Zealand, who have won all four of their group matches, need only one victory from their remaining two games – against Afghanistan and Bangladesh – to secure their place in the quarter-finals.
Tournament favourites Australia, meanwhile, have three points from their first three games, heading into Wednesday’s clash with Afghanistan in Perth.
Australia captain Michael Clarke, playing his first competitive international since December following hamstring surgery, said: “Our batting was horrendous, to put it mildly, but Mitchell Starc was a genius.”
This was only the sixth one-wicket win in World Cup history, although such a slender margin of victory appeared unlikely in the extreme as Brendon McCullum flayed a 21-ball fifty to lead the Kiwi pursuit.
Even after he fell in the eighth over to spark a collapse of three wickets in five balls – Ross Taylor and Grant Elliott were bowled by Starc either side of the interval – few doubted the outcome.
Williamson and Corey Anderson took New Zealand to within 21 runs of victory before Glenn Maxwell induced an ugly swipe from the left-hander that found only mid-on.
Starc, combining fast, full deliveries with well-directed bouncers, had an evasive Luke Ronchi caught behind off his glove, then Cummins accounted for a needlessly reckless Daniel Vettori.
New Zealand nerves were evident as Starc cleaned up Adam Milne and Tim Southee with successive deliveries, but Boult kept out the last two balls of the over and Williamson drove the first ball of the next over long-on to cap a remarkable game.
“My heart was racing at a million miles an hour when I went out there to bat. I’ve never been so nervous in my career,” Boult told Test Match Special.
Even Starc’s career-best return could not mask an inept Australia batting display that featured a precipitous collapse from 80-1 to 106-9.
While fellow left-arm Boult was the chief beneficiary en route to his best ODI figures, Vettori’s impact was crucial.
Introduced only six overs into an innings which began with a barrage of boundaries, the veteran left-arm spinner accounted for Shane Watson and Steve Smith either side of Tim Southee’s removal of David Warner for 34.
Vettori finished with 2-41, while Boult claimed five wickets for one run in 17 balls in front of a boisterous home crowd en route to his best ODI figures.
Even Brad Haddin’s pugnacious 43 in a last-wicket stand of 45 with Cummins – an Australia World Cup record – could not prevent Australia posting their lowest World Cup total batting first.