World Cup: New Zealand Edge Australia in Stunning Finish

New Zealand booked their place in the World Cup quarter-finals with a narrow one-wicket win over Australia in a sensational finish to their Pool A match in Auckland on Saturday. (Scorecard)

With six needed for win and just one wicket in hand, Kane Williamson (45 not out) hit Pat Cummins for a straight six to seal the victory, to the delight of most of a packed 40,000 crowd at Eden Park, who saw their side almost snatch defeat from the jaws of victory.

Australia fought back through a career-best six for 28 from Mitchell Starc who almost sealed an unexpected win for the four-times former champions.

Earlier, Trent Boult -- like Starc a left-arm seamer -- took a career-best five for 27 saw Australia dismissed for just 151 all out in 32.2 overs before New Zealand struggled to reach their victory target in 23.1 overs, despite skipper Brendon McCullum's 24-ball 50.

New Zealand now have four wins in as many group games and on course to claim top spot in Pool A, while fellow co-hosts Australia have three from their first three fixtures following a 111-run win over England and a no result wash-out with Bangladesh.

The Black Caps were crusing at 131 for four but lost their next five wickets for 15 runs in the space of 19 balls.

The slide started with Glenn Maxwell dismissed Corey Anderson for 26 after the left-hander and Williamson put on 52 for the fifth wicket.

Starc then dismissed Luke Ronch (six), Daniel Vettori (two), Adam Milne (nought) and Tim Southee (nought) to give Australia a sniff of an unexpected win before Williamson held his nerve.

Earlier, McCullum hit three sixes and seven fours to give New Zealand an ideal start to their run-chase.

But it was Boult who derailed Australia after the visitors won the toss and batted on a flat pitch.

Boult triggered Australia's slump to 106 for nine, having been well-set at 80 for one.

It was only thanks to a last-wicket stand of 45 between Brad Haddin (43) and Cummins (seven not out) that Australia got past their lowest World Cup total of 129 against India at Chelmsford in 1983.

Haddin was the last man out, caught of Anderson after hitting four boundaries and two sixes off 41 balls.

Southee took two for 65 while left-arm spinner Daniel Vettori, who did a superb job in slowing Australia's early run-rate, finished with two for 41.

Australia's batting was in a state of chaos as they lost eight wickets for 26 runs in nine overs, with left-arm seamer Boult taking three for five in his second five-over spell.

David Warner, who made 34, gave Australia a confident start in an opening stand of 30 with Aaron Finch (14).

But once Warner and Shane Watson (23) fell off successive deliveries, the innings fell apart.

Warner and Watson looked well set during their 50-run stand for the second wicket but Watson holed out off Vettori's last ball of the 13 over.

Southee removed Warner leg-before off the first ball of the next over.

Boult, who had figures of 5-0-24-0 in his first spell, removed Glen Maxwell (one) off the inside inside edge and then, two balls later, had Mitchell Marsh playing on for a second-ball duck.

Australia captain Michael Clarke, playing his first international since December following a hamstring injury, drove stright into the hands of short cover in Boult's next over and was out for 12.

Boult then bowled Mitchell Johnson and Starc in his next over to better his previous ODI best of four for 44 against Sri Lanka at Dunedin last month.