South Africa actually started strongly, dominating the early scrum exchanges as they piled the heat on rookie All Blacks props Kane Hames and Nepo Laulala.
It was a performance that showed when the All Blacks click there is a huge gulf between the first and third ranked sides two years out from the next World Cup, and left Springbok coach Allister Coetzee distraught.
"We have no option but to fight back in South Africa".
"I won't say it was a horror movie but." he said, searching for words to describe his disappointment.
They scored three long range tries with Ioane, Milner-Skudder and Retallick all crossing after the world champions identified space behind the defensive line.
The All Blacks ran out 57-0 winners, scoring eight unanswered tries in keeping the Springboks scoreless for only the fifth time in their 94-Test history.
Barrett's goal-kicking had been questioned when he missed all three of his attempts during the All Blacks' Rugby Championship Test against Argentina, but he returned to form yesterday, kicking eight of nine attempts for 17 points.
Despite the lopsided scoreline, the opening stanza belonged to South Africa when Eben Etzebeth, Jean-Luc de Preez and Uzair Cassiem led a muscular approach. But their dominance was hindered by handling errors and a chance to put points on the board via a penalty by the usually reliable Jantjies fell short.
With four wins from four, the All Blacks are now in pole position to retain the Rugby Championship, with trips to Buenos Aires and Cape Town to come.
Though the try will be credited to Milner-Skudder, it was Beauden Barrett who ensured it will take a place on the highlight reel of tries from 2017.
Replacement Scott Barrett also crossed after his older brother Beauden cross-kicked for Dane Coles to knock the ball down to the 23-year-old, who was on the field as Liam Squire underwent a head injury assessment.