The Kiwis raced to a stunning victory with 23 overs to spare after fast bowler Shane Bond had destroyed the Australian batting line-up by taking 5-23 in their miserable total of 148.
New Zealand had little trouble reaching their target with Lou Vincent sealing the win by smashing Mitchell Johnson for six to finish unbeaten on 73 with skipper Stephen Fleming not out 70.
The Australians were missing five key players – Ricky Ponting, Adam Gilchrist, Andrew Symonds, Brett Lee and Michael Clarke – but their absence could hardly be regarded as an excuse for their fourth defeat in five matches and their first 10-wicket loss in 646 One-day Internationals.
“It's not a nice feeling. It's a demoralising loss and probably as low as we've been,” stand-in captain Mike Hussey said in a televised interview.
“Everything seemed to go the wrong way and it can only go up from here.
“We've got a new group at the moment and we've just got to mould together as quickly as possible.
“It was a good toss to win and they got plenty of movement out of the wicket. I was hopeful a couple of early wickets would give us a chance, but we couldn't get any momentum.”
Beaten 2-0 by England in the tri-series finals last week, the out-of-form Australians are now on the verge of losing their number one ranking to South Africa if they lose the three-match series in New Zealand, while their World Cup preparations are in tatters.
Hussey top-scored with 42 off 96 balls while Brad Hodge (22) and Brad Hogg (20) both made starts but only two other players reached double figures as the Kiwis chalked up their first win over Australia this year after losing all four tri-series clashes.“Everything for them went wrong and everything for us went right, right from the toss,” Fleming said. “They had the worst of the pitch, it got better for us and we rode our luck.
“It's the best I've seen Shane bowl for some time and not just because he got five wickets. His control was outstanding, and his thought processes were great.”
Bond, who took a hat-trick against Australia in Hobart last month, continued his success against them with a supreme display of fast bowling.
He removed replacement opener Phil Jacques (one) and Gilchrist's standby wicketkeeper Brad Haddin (six) in his first spell, then took a superb one-handed catch to remove the dangerous Cameron White (13) in his second spell.
Bond completed his fourth five-wicket haul in One-day Internationals when be clean bowled Nathan Bracken for a duck then dismissed Hogg to polish off the Australian innings inside 50 overs.
Vincent and Fleming each hit eight fours and two sixes in their unbroken partnership, with Vincent reaching his half-century off 61 balls and Fleming silencing his critics by bringing up his fifty off 62 deliveries.
However, New Zealand's win may have come at a price with explosive all-rounder Jacob Oram breaking a finger after taking a routine catch off Johnson, threatening his World Cup chances.
The teams meet in the second match of the series in Auckland on Sunday with the third and final game in Hamilton on Tuesday.
Scoreboard
AUSTRALIA:
M.L. Hayden c Fleming b Gillespie 14
P.A. Jaques c Vettori b Bond 1
B.J. Haddin b Bond 6
M.E.K. Hussey c Taylor b McMillan 42
B.J. Hodge c Fleming b Vettori 22
C.L. White c and b Bond 13
S.R. Watson c Bond b Vettori 8
G.B. Hogg b Bond 20
M.G. Johnson c Oram b Gillespie 8
N.W. Bracken b Bond 0
G.D. McGrath not out 5
EXTRAS (B-1, LB-2, W-5, NB-1) 9
TOTAL (all out, 49.3 overs) 148
FALL OF WKTS: 1-3, 2-16, 3-45, 4-86, 5-98, 6-108, 7-120, 8-133, 9-133.
BOWLING: Tuffey 8-0-29-0 (1w); Bond 9.3-23-5 (1nb, 2w); Oram 10-0-22-0; Gillespie 9-0-27-2 (1w); Vettori 9-1-26-2; Styris 2-0-15-0 (1w); McMillan 2-0-3-1.
NEW ZEALAND:
L. Vincent not out 73
S.P. Fleming not out 70
EXTRAS (LB-3, W-2, NB-1) 6
TOTAL (for no wkt, 27 overs) 149
DID NOT BAT: R.L. Taylor, S.B. Styris, C.D. McMillan, J.D.P. Oram, B.B. McCullum, D.L. Vettori, S.E. Bond, M.R. Gillespie, D.R. Tuffey.
BOWLING: McGrath 6-1-23-0 (1nb); Bracken 7-1-30-0; Johnson 8-0-49-0 (1w); Watson 4-0-28-0; Hogg 2-0-16-0 (1w).
RESULT: New Zealand won by 10 wickets.
UMPIRES: B.F. Bowden (New Zealand) and Aleem Dar (Pakistan).
TV UMPIRE: G.A. Baxter (New Zealand).
MATCH REFEREE: M.J. Procter (South Africa).
MAN-OF-THE-MATCH: Shane Bond.
SECOND MATCH: At Auckland on Sunday.
THIRD MATCH: At Hamilton (D/N) on Tuesday.—Agencies