Then came his desperate high shot on Smith following a superb run and pass from the electric Nehe Milner-Skudder, who has almost certainly booked his place on the plane for the World Cup, and that was effectively that. Ma'a Nonu and Conrad Smith also crossed while he was cooling his heels and the score quickly blew out to 34-6.
Cheika, who replaced Cooper with Kurtley Beale once his time in the bin was over, has already promised the New Zealand-born player a place in his World Cup squad. Will he regret that?
There was pressure, too, on Cooper's opposite Dan Carter after the defeat in Sydney last weekend, but he responded with a consistently good performance and a piece of brilliance to unlock the visitors in the first half.
In his final test in New Zealand, he needed to run and he did. The Wallabies defence had been so good for the opening quarter it was an almost surreal sight to see him step his way through the green-and-gold wall.
The Australians were on the back foot due to Julian Savea's charge down the left - capitalising on a brilliant steal by Sam Whitelock in his own 22m area - and then Carter was off, using a clever head fake and then accelerating away.
With Dane Coles in support it seems just about anything is possible, and the hooker reprised his exploits in Johannesburg a few weeks ago with an even better try; helped by Adam Ashley-Cooper's slip such was Coles' lightness of foot.
It was just what the All Blacks needed, for their start was a nervous one, just as it was in Sydney. Brodie Retallick's fall in contesting the kickoff would have created some anxiety in the coaches' box, too, given Steve Hansen's gamble at not carrying a specialist lock on the reserves bench.
Hansen's roll of the dice paid off, though. Cheika's didn't. Bledisloe Cup locked up for another year.
