The All Blacks scored two of their tries while he was off the field.
Dan Carter added 16 points from the boot in captain Richie McCaw’s record 142nd test match as the world champions stamped an emphatic message to their challengers they would not relinquish the Webb Ellis trophy easily next month.
Cooper slotted two first-half penalties while Israel Folau scored a consolation late try for the visitors, who had hopes of clinching the Bledisloe Cup for the first time since they lost it in 2003 after a 27-19 victory in Sydney last week.
“That was a performance the whole country can be proud of and we in the team are incredibly proud of,” All Blacks coach Steve Hansen said. “It’s more of what we expect from our group and this goes to show we were well off the pace last week.”
While the lessons from Sydney did not seem to have been learned by the home side in the opening quarter when they were error-prone and kicked much of their possession away, the Wallabies barely featured in the final 60 minutes.
A turnover by Sam Whitelock deep inside his own territory after a succession of Wallabies attacks in the 21st minute that led to Coles’ try changed the momentum of the game.
The All Blacks went into halftime with a narrow 13-6 lead, but came out in the second half with improved accuracy, intensity and decision making.
Their forwards cleared out at the breakdown, phases were built and they allowed the backs to run more directly at their opponents.
Carter used that extra space to finally re-discover his running game that had appeared to have deserted him for several years, while Nonu’s hard straight bursts got them over the advantage line and punched holes in the defence.
The All Blacks had put the Wallabies under immense pressure before Cooper’s indiscretion, though Michael Cheika’s gamble to play the flyhalf despite his history of poor performances against the New Zealanders did not bear fruit.
Several of Cheika’s other selection gambles, notably Will Skelton, Wycliff Palu and Henry Speight, were mostly anonymous and but for Folau’s try from a wayward cross-kick, the score could have been more damaging to their confidence ahead of the World Cup.
“We knew it would be tough but we got outclassed tonight,” Wallabies captain Stephen Moore said. “Full credit to Richie and his team.”
(Reporting by Greg Stutchbury in Wellington; Editing by Sudipto Ganguly)