The 28-year-old Williams captured a career-best four for 22 and left-arm Bracken three for 25 as the New Zealanders, who opted to bat in swinging conditions, were dismissed in 33.4 overs for their fifth lowest one-day international total.

Matthew Hayden then made a run-a-ball unbeaten half-century, sealing the win on his 32nd birthday with a leg-side drive for four in the 17th over.

Adam Gilchrist hit five fours and a mid-wicket six off 18 balls as he made 29.

New Zealand's highest contribution came from extras.

"It was a very good toss to lose. I was actually going to bat -- we might have lost," Australia captain Ricky Ponting said with a smile.

"I expected the ball to swing a bit. Nathan is a swinger of the ball and Brad swings it too."

Williams and Bracken made light of lack of experience -- having played just 20 games between them -- with lively pace and fine control as the ball swung for the first hour.

By then the match was as good as over. The pair, filling in for the injured Glenn McGrath, Jason Gillespie, Brett Lee and Michael Kasprowicz, reduced New Zealand to 21 for five in nine overs.

Craig McMillan (24) and Chris Harris stemmed the rot with a 52-run sixth-wicket stand before seamer Ian Harvey trapped left-hander Harris lbw to make it six for 73.

Harvey claimed two wickets for nine runs from eight overs and Andy Bichel took the other wicket in excellent support roles.

The world champions once again revealed their spirit and depth of ability, having lost by 37 runs to India on Sunday. It was their fourth straight win over the New Zealanders.

Only three Kiwi batsmen reached double figures.

Bracken struck with the second delivery of the morning by trapping opener Chris Nevin lbw for nought with a delivery which straightened after pitching.

He then forced an uncertain Stephen Fleming, who made 39 in three innings in the drawn two-Test series, to edge a seaming delivery to wicketkeeper Gilchrist.

Williams made it 11 for three next over when a frustrated Lou Vincent skied an attempt slog to short mid-off for a 11-ball duck.

The Western Australia bowler then forced Scott Styris to edge a drive to Ricky Ponting at second slip for seven and Bracken had all-rounder Jacob Oram caught behind.

Bracken's figures read 4.4-2-7-3 at that stage.

Williams, whose previous one-day best was two for 22, took the last wicket, Paul Hitchcock caught at slip.