"I thought we put a lot of pressure on them with our defence and they came up with a couple of errors, they are only human," said Mannering, who enjoyed his third career win over Australia. "We put pressure on them and that happens sometimes."
The Kiwis grew more dominant as the match wore on last night. From a fairly even first half, the New Zealand side seemed to lift to another level in the second half, and Australia had few answers with or without the ball.
The black and white wall was almost impregnable in the second spell, while their attack was full of flair, and the Kiwis utilized their full range of skills with some stunning second phase play.
"It was a great performance," said Kearney. "I think we played a style of footy [last night] which is a Kiwi style of footy."
However, both captain and coach were preaching caution, recognising that:
• circumstances had conspired against Australia and
• the Four Nations still has three weeks to run.
"It's great to get off to a start like that in the tournament and I thought the boys performed really well," said Kearney.
"[But] I'm not doing cartwheels. I'm pretty philosophical in the sense that we got a couple of lucky breaks; they had a couple of key players in their side [Daly Cherry-Evans and Greg Inglis] who didn't come back on after halftime. And we are very mindful that it is just one step, the first step in a pretty tough couple of weeks."
"We've got to build on this performance if we want to be there or thereabouts in Wellington [for the final]," added Mannering. "I know [Australia] will be better for it [and] it's the first step in a tough tournament. [Australia] had a couple of blokes taken off at half-time - though that's taking nothing away from our performance."
"We know we have to keep building through this competition because it doesn't get any easier with Samoa and England," continued Mannering. "We are heading in the right direction but there is still a long way to go."
Kangaroos 12 (B. Scott, G. Inglis try; C. Smith 2 gls) Kiwis 30 (K. Proctor, L. Brown, S. Johnson, D. Whare, J. Nightingale tries; S. Johnson 5 gls). Halftime: 12-12
The Kiwis next match is against Samoa in Whangarei on Saturday at 4pm. Australia faces England in Melbourne the following day.