This is the view of All Black coach Steve Hansen.
But he is equally adamant his defending World Cup champions will have to improve their discipline after two of his most senior on-field architects - Richie McCaw and Conrad Smith - were yellow carded against Argentina.
He put New Zealand's struggle to overpower the South Americans, and South Africa's last gasp defeat by rugby minnows Japan, as opening match nerves - with both sides remaining serious contenders to make the final still six weeks away.
In a post-match review on Monday, a day after the All Blacks took until the last 20 minutes before getting on top of Argentina to win 26-16, Hansen remained upbeat about his side's chances of defending their world crown
"We got out of it exactly what we wanted. A tough contest, a challenge in some areas, some areas we've got to improve on, but the most important thing is we got a win."
He said no team should under-estimate the All Blacks on the basis of that Pool C match, nor South Africa after their shock 32-34 loss to Japan in Pool B
"It doesn't matter what they think. It would be very foolish for anyone to think that they could rock up and take South Africa lightly now because Japan's beaten them. It's irrelevant what happens game to game.
"It's what's happening in the game you're playing in at that moment. If you've got talent and ability to improve then it's a different beast you're going to get the next time you play.
"We've got talent and we've certainly got the ability to improve."
However, the All Blacks definitely need to play closer attention to discipline after conceding nine penalties, including two yellow-card offences.
"Clearly, the referees have a mandate to come down hard on things and you don't have to be a rocket scientist to know it's better to have 15 players on the park than 13 - like we did at one stage," Hansen said.
"Discipline is going to be important. We were fortunate we came through while those two guys were off."
Hansen described the opening weekend of the World Cup as "great" for the game with Japan's historic win inspiring other so-called second tier nations that rugby was not dominated by a handful of teams.
"What it does for the likes of the Uruguay and Namibia and those lower order teams is give them a change of mindset that 'we can compete if we prepare well'."
Hansen, a close friend of South African coach Heyneke Meyer, said that despite the Springboks loss they can still win their pool which also includes Scotland, Samoa and USA.
"It's not all lost and they still qualify if they get second. that's the beauty of pool play. It hurts more when it happens in the knockout stages because all you do then is go home, and it's all over and you don't get another chance.
"They'll get another chance. I'm sure they'll improve immensely because of it. They're they're a very good side."
The All Blacks next game is against Namibia on Thursday while South Africa have a break until Saturday when they play Samoa.
Agence France-Presse
