New Zealand head coach Steve Hansen admitted that going to uncontested scrums played a major role in their win at Ellis Park.
South Africa lost both Jannie du Plessis and Vincent Koch to injury and Hansen said the difference between winning and losing was a crucial period around the hour mark when the All Blacks were able to keep the Boks out while camped on the Kiwi tryline.
"We defended with all our hearts," said Hansen.
"Had they scored there it would've been hard to come back. We showed mental fortitude and the physical ability to keep getting up and making our tackles and force the turnover.
"Unfortunately for them, one of their guys was injured. No one in the world has three tightheads, so we had to go to 'golden oldies scrums'.
"We were down to seven men versus eight [after Sam Whitelock had been yellow-carded]. That would have been a tough spot to get out of.
"So that [injury] was a massive turning point."
Saturday's Test was another close finished between the top two sides in the world, with Hansen admitting that the win could have easily been a loss.
"I'd say the last three games [between the teams] over here could have gone either way," said Hansen.
"They're developing a style of play that's going to be difficult to combat. They have some very exciting young backs and a lot of pace in their backline and some brutal forwards.
"Heyneke has done a good job of developing [the team] over the last two or three years. They're the No 2-ranked side and as you saw tonight there's nothing between the top team and the second-placed team."
Richie McCaw admitted NZ were under the cosh in first half but was proud of the way his side hung on to win at the death.
"That's part of sport. It's not always going to go your way for 80 minutes," he said.
"But we've been in those situations before, so that helped us. After that we had one or two chances and made them count. We're proud of that but not the overall performance.
"He comes down to self belief, but you'd like a bit more to go your way than it did tonight because quite oftern you lose those games."
The All Blacks have a few injury concerns of their own but Hansen revealed that Brodie Retallick injured his ankle before kick-off, with the World Rugby Player of the Year going on to impressively play a full 80 minutes.
"We thought we have to make a late change and bring in Luke Romano," said Hansen.
"It was a testiment of his courage and toughness that he actually got through the game."