All Blacks captain Reuben Thorne admitted his side need to improve despite scoring another 10 tries in a 68-6 victory over Italy.
New Zealand struggled to impose themselves in the first quarter at Melbourne's Telstra Dome against a committed Canadian side.
"It was pretty frustrating at times - there were a lot of mistakes out there," Thorne said.
"But you have got to give credit to Canada. They really defended terrifically and we just couldn't get a flow on.
"That is probably to be expected with all the changes we made but even so it was very frustrating.
"We'll take the points for sure but we really need to lift our performance over the next two weeks."
Wing Mils Miliaina did enjoy a memorable match however, becoming the 10th player, and fifth New Zealander, to score four or more tries in one World Cup match.
"It was nice to get a few easy ones," he said. "It was pretty good out there.
"We wanted to get the ball rolling and in the second half it just seemed to flow."
All Blacks coach John Mitchell hailed "a very good workout" for his side.
"We lost a bit of rhythm in the first 30 minutes," he admitted. "Canada played their hearts out.
"It was exactly what we needed. We had to work hard for that