Seeking to avert a third successive defeat, and a second home reverse in the tournament following the triumph by the South Africans in Dunedin, the All Blacks were always on the front foot in Auckland and eventually ran out 39-10 victors.
But having eased their way ahead - they led 21-10 at the break - with three tries, coach Graham Henry was hoping for a fourth touchdown to clinch a vital bonus point.
It eventually came with the last move of the match when Nonu raced 40 metres before diving over in the left corner.
He was tackled by Loti Tuquiri as he dived for his second try and South African referee Mark Lawrence had to consult with his video official before confirming the score.
It was a vital decision because the bonus pint put the All Blacks a point ahead of the Wallabies in the Tri Nations table and took them five points clear of the Springboks.
As well as two tries for blockbusting centre Nonu, the home side also had two close range tries from prop Tony Woodcock to savour. There were also 19 points from the boot of Dan Carter to take him through the 800 international points barrier.
If the Springboks want to add the Tri Nations title to their World Cup crown then they will have to close the gap on the All Blacks when they meet in Cape Town on 16 August. Then they meet the Wallabies in Durban and Johannesburg over the following two weekends.
After a traumatic week in the wake of their heavy defeat against Australia in Sydney the previous weekend, returning New Zealand skipper Richie McCaw was full of praise for his side.
And he also had a warning for the Springboks ahead of their third clash in the competition in two weeks time.
"We have set a standard with this win and we have got to get better from here. When your backs are against the wall you have to come out and show what you are made of," said McCaw.
"When you lose two games in a row it is a measure of how you get back on the horse. We had been hurting all week and we wanted to put together a big performance."