Nienaber said one of the main work-ons for the team leading up to their opening Rugby World Cup clash against Scotland in Marseille on Sunday 10 September, was to round off the opportunities they create after allowing several chances to go begging in London.
Despite this, the Springboks outscored the All Blacks five tries to one.
“This was a proper test, and it was exactly what we wanted before the World Cup,” said Nienaber.
“Wales play a different style of rugby to New Zealand, who pride themselves on their high intensity and high tempo game, so it was good preparation for us.
“That said, we have hard work ahead before the World Cup. We had several opportunities to score tries which we didn’t convert, so we’ll zoom in on that in Corsica and hopefully we can improve on that before our opening match.”
Springbok captain and flanker Siya Kolisi praised the 80 000-strong crowd that made their way to Twickenham – most of whom were South African supporters – on what was a neutral ground for both teams.
“It was amazing to see the number of South Africans lining the streets on the way to the stadium," said Kolisi, who scored the Boks' first try.
"The coaches told us before the match that whenever we need them they are here for us, and they came out strongly today. That’s why we couldn’t hold back in this match, we had to give it all, and we did that as a team.”
Commenting on the late injury withdrawal of Willie le Roux, who was replaced by Kwagga Smith after battling to recover sufficiently from a knock to the ribs at training, which saw a seven-one split in favour of the forwards on the bench, Nienaber said: “It was an unfortunate incident and we didn’t want to risk Willie.
“With the way games have been playing out, there are times when your forwards have to play in the backline, and this offered us the same option.
“It gave us a taste of how to manage things if we perhaps get an injury in a match. Obviously, the least risk would be selecting a five-three split, and a six-two split holds a little more risk, and then a seven-one split is the most-high risk.”
The Springboks will depart for a week-long training in Corsica on Saturday and will arrive at their Rugby World Cup base in Toulon on Sunday, 3 September.