Head coach Ian Foster said the All Blacks need to keep their heads during their northern hemisphere tour after being made to sweat for their 38-31 win over Japan in Tokyo on Saturday.
New Zealand conceded four tries and lost lock Brodie Retallick to a 66th-minute red card as they kicked off their tour against a spirited Japanese side that trailed by only four points heading into the final minutes.
Foster said the All Blacks were "a bit rusty" playing their first game in more than a month and would need to get up to speed quickly with away games against Wales, Scotland and England to come.
"There are a number of things we have to improve from today but I think we've had five weeks without a game and that sort of showed in some of our timing," said Foster.
"I think there were moments where we weren't composed. When the game doesn't go your way for spells and you're away from home, it's easy to lose confidence and lose shape."
The All Blacks scored three first-half tries through Retallick, Braydon Ennor and Sevu Reece, but Japan hit back with two of their own to head into half-time trailing by only four points.
Caleb Clarke and Hoskins Sotutu scored two more for New Zealand after the interval, but Japan would not be shaken off and a red card for Retallick for dangerous play at a ruck set up a nervy finale.
- 'A lot of pressure' -
Kazuki Himeno scored Japan's fourth try to turn the screw in the dying moments but Foster said he was happy that his side "stayed tight through some key points".
"We got put under a lot of pressure but I really liked the way we played," he said.
"Japan came back very well before half-time and really turned the game into a tight contest. Some new combinations, and overall it's a good stepping stone for us."
Japan were looking for their first-ever win over the All Blacks and head coach Jamie Joseph said his team's "intent was very clear from the start".
Takuya Yamasawa and Yutaka Nagare scored first-half tries and lock Warner Dearns added another after the break, after charging down a kick from All Blacks scrum-half Finlay Christie.
"It was exactly what we're trying to build as a rugby team," said New Zealand-born Joseph.
"I thought our team played very well and we created a chance to win the Test match, which would have been a historical moment for Japanese rugby if we had been able to pull that off."
Japan were given a chance when Retallick saw red for charging into Himeno at a ruck with 14 minutes of the match remaining.
Foster said he had "no complaints" about the decision.
"To be down to 14 men for the final 15 minutes, we just focused on the moment in front of us," said New Zealand captain Sam Cane.
"The belief was very strong and we didn't want to force anything, so stay disciplined, trust each other and work hard."
- 'Too many mistakes' -
New Zealand next play Wales in Cardiff before taking on Scotland at Murrayfield and England at Twickenham.
The All Blacks won the Rugby Championship last month but have endured a turbulent year that has included a home series loss to Ireland, a heavy defeat in South Africa and a maiden loss on home soil to Argentina.
Fly-half Richie Mo'unga said they would need to shape up against their British opponents.
"Probably the problem-solving part, just getting to solutions a bit quicker," he said when asked what the All Blacks would have to improve.
"I think northern hemisphere teams are going to be a bit more unforgiving in that part of the game."
Japan will also head to Europe to play England at Twickenham and France in Toulouse.
"Now we realise that if you make one or two mistakes then your opportunity to win the game passes you by," said Joseph.
"The crux of it really is that we made too many mistakes at the wrong time, but everything else around the game in terms of how we wanted to play and what we needed to do was really, really good."