It was the first All Blacks win at home against their greatest rivals since the 57-0 debacle at North Harbour Stadium in Albany in 2017.
It took 68 minutes, especially after a two-try second burst by South Africa, but that man Will Jordan latched onto a chip ahead from first receiver Beauden Barrett to get the ball down at his second attempt to give the All Blacks a 15-point buffer.
South Africa threw plenty at the home side, but the defences held for most of the final 12 minutes. Then after infringements started to mount, the All Blacks got into the Springboks 22m area where the pack went to work and from a five-metre scrum No8 Ardie Savea detached with the ball, and a vast blindside gap opened through which Mo'unga raced to extend the lead.
There was a belated try to Springbok flanker Kwagga Smith when stealing the ball from an All Blacks ruck, but in the 79th minute, it was too little, too late. It didn't help that fullback Willie le Roux's attempt to take a quick conversion hit the upright and bounced back into the field of play.
It was a reward for the All Blacks' positive intent from the opening phases, but they could not maintain the momentum long enough to put the foot on the South African throats.
First five-eighths Richie Mo'unga was in outstanding touch, scoring a try and kicking 12 points, while the pack was again belligerent in conceding nothing to the bigger touring side and continuing to form an impressive role in supporting their backs in moving the ball at speed from the second phase play.
They ran the ball at South Africa from the outset during an electric 20 minutes, which went close to running the Springboks ragged. By the end of the half, the All Blacks had made five clean breaks to none and managed seven offloads to three; South Africa also missed 19 tackles to only 11 by the All Blacks.
While the All Blacks kicked more, 17-7, several were foot passes, especially to Will Jordan's right wing.
The All Blacks scored the opening try four minutes into the game after the play ranged left and right, stretching South Africa's defence with snappy passes and miss-out balls that reached finality when right-wing Will Jordan was tackled. He quickly played the ball again, stepped inside and made ground before finding halfback Aaron Smith inside to take the pass and score.
They could have scored earlier after a stunning midfield burst by flanker Shannon Frizell but play broke down, and South Africa kicked deep into New Zealand territory. The All Blacks worked the ball back downfield with a second five-eighths Jordie Barrett and wing Mark Telea moving the ball.
However, Frizell had his reward in the 14th minute, when the All Blacks split the Springboks again with a series of breaks that finally saw the fastball moved to the left flank, where hooker Codie Taylor ran onto a pass hard and fed Frizell outside. He charged along the sideline to touch down wideout.
Moments later, South Africa was lucky to avoid embarrassment when attempting a quick throw of their own. The recipient, No8 Jasper Wiese, dropped the ball cold but was ruled to have been taken out with a high tackle after the referee Mathieu Raynal had blown his whistle.
South Africa went close in the 25th minute when a try for wing Cheslin Kolbe, after contesting a high kick on the line with All Blacks fullback Beauden Barrett was ruled a knock-on in goal. The resulting goalline dropout was knocked on by Springbok's second five-eighths Damian De Allende on their 10m line, but halfback Faf de Klerk contested the ball at the back of the All Blacks scrum.
However, when the South Africans when the All Blacks cleared their 22m area, they stole South Africa's lineout ball. De Klerk did opt to kick for a goal in the 35th minute, but soon after, when the halftime hooter had sounded, South Africa kicked to the corner from a penalty. They had several attempts at getting the ball over the line, but the All Blacks' defence held, and when Raynal asked for the TMO to see if the ball had been grounded, his request was over-ruled because lock Lood de Jager had neck-rolled an All Blacks defender in the earlier play.
Down 3-20 at the turn, South Africa made several changes in the first 10 minutes of the second half, and one of them, hooker Malcolm Marx made the most of the side's first successful lineout drive to score their first try, 53 minutes into the game.
Then as the fresh men ran the ball up to commit the All Blacks defence, South Africa moved the ball more effectively than any time earlier, and wing Cheslin Kolbe dived over in the corner after the TMO assessed a marginal pass to him was not forward.
Scorers: New Zealand 35 (Aaron Smith, Shanno Frizell, Will Jordan, Richi Mo'unga tries; Richie Mo'unga 3 con, 2 pen) South Africa 20 (Malcolm Marx, Cheslin Kolbe, Kwagga Smith tries; Faf de Klerk pen; Kolbe con). HT: 20-3