The loss would take the pressure off the All Blacks in this World Cup season as going into the RWC unbeaten for the season would be counter-productive. The following is the match report from the All Blacks official website:
All Blacks Silenced By Resurgent Wallabies
New Zealand paid dearly for the loss of prop Carl Hayman in the middle stages of the second half of a torrid Bledisloe Cup/Philips Tri Nations contest against Australia in Melbourne and suffered its first defeat of the season 20-15.
(All Blacks captain, Richie McCaw baing taken down)
Hayman was sin-binned for playing the ball in the tackle and the Australians pounced to score two tries and snatch the lead from the All Blacks.
Earlier, Australia had seemed bereft of ideas of how to breach solid All Blacks defence.
But suddenly it found the loss of Hayman created the space it needed and it scored through wing Adam Ashley-Cooper and replacement back Scott Staniforth to take the lead with 10 minutes left in the match.
At that point Hayman returned and New Zealand tried to regain the control it had lost at his departure. But it had given the Australians too much leeway and was unable to find the openings that had been more available earlier.
Skipper Stirling Mortlock gave an outstanding display for the Wallabies and set the crowd of 79,322 alight with his decisive line breaks.
The first try, to Ashley-Cooper, was the result of intense movement of the ball from the penalty that saw Hayman dispatched, but the second came from centre Mortlock's second backline bust of the evening.
He beat makeshift centre Luke McAlister with disarming ease and kept racing toward the goal-line, finally unleashing the try-making pass to Staniforth.
New Zealand could look back at numerous lost opportunities due to handling chances in the first 60 minutes of the game that should have seen it well in front.
The play, in the first half especially, was frenetic at times with several of the New Zealanders making powerful surges with the ball in hand. Captain Richie McCaw and prop Tony Woodcock were outstanding, with McCaw giving his best display of the season to date.
At the first lineout, moments into the game, No 8 Rodney So'oialo secured clean ball to flanker Jerry Collins, who then set up skipper McCaw for two powerful surges at the line.
Fullback Mils Muliaina set up the maul when fed an inpass and then it was Woodcock who drove over to convince the television match official that he had grounded the ball.
From the re-start Australian lock Nathan Sharpe took Troy Flavell out and the penalty was awarded. However, Australia secured the lineout ball and mounted a series of assaults at the New Zealand line, but fine All Blacks defence saw the Australians fail to get past the advantage line.
Australia came back with some well-directed play from first five-eighths Stephen Larkham. He fired a well-placed kick to the corner and flanker George Smith did well to follow up and secure.
While no try was forthcoming, the All Blacks backs were penalised and Mortlock made no mistake with his second attempt.
Moments later, however, the Wallabies on their own 22m line interfered with halfback Byron Kelleher as he attempted to clear the ball. Carter made no mistake with the goal after 16 minutes.
Mortlock kicked a second penalty after 19 minutes when the All Blacks were penalised at the scrum.
The Australian scrum came under pressure, twice conceding penalties and on the second occasion after 25 minutes, Kelleher took a quick tap and the ball was moved quickly with Woodcock prominent again charging ahead.
Then with the quick turnover, McAlister, who had set the whole momentum with his superb intercept and run into the Wallabies 22m, took the tackle and fed right wing Rico Gear in for the second try.
The situation might have been even worse for the Australians had the All Blacks not left the ball exposed at the back of a ruck which allowed the Wallabies to clear out, but then when the All Blacks recovered, a superb build-up created by Muliaina broke down when So'oialo dropped the ball.
But at the resulting scrum, the All Blacks powerhouse destroyed the Wallabies scrum and turned the ball over.
Mortlock made a superb break, went through Muliaina's tackle and set up the chance but the opportunity was lost as prop Guy Sheperdson drove to the line, but was ruled to have made a double movement.
New Zealand then replaced Woodcock, hooker Anton Oliver and lock Flavell with Neemia Tialata, Keven Mealamu and Ross Filipo.
Clearly the coaching staff were looking to counter the possible effects of the travel associated with the return from South Africa but ultimately, the New Zealanders were unable to finish at the pace they achieved to come from behind in South Africa last week.
Australia 20 (Adam Ashley-Cooper try; Matt Giteau con; Stirling Mortlock 2 pen)
New Zealand 15 (Tony Woodcock, Rico Gear tries; Daniel Carter con, pen)