The All Blacks were 16-15 down with little over quarter of an hour to play at the Millennium Stadium, but they stepped up a gear to pile on 19 unanswered points.
It was a superb demonstration of New Zealand at their best as Wales, who barely put a foot wrong, were simply outclassed in a 34-16 loss against a side they have not beaten since 1953.
Despite not wrapping up the win until the closing stages of the game, Hansen felt his side always had it in them to get the job done.
"I don't think that we wriggled off the hook," he told BBC Sport. "The game's played for 80 minutes and you've got to play for 80. I'm proud of the boys. We haven't always played the best but we've found a way to win.
"The players have a lot of pride in themselves and collectively as a group. We put them under a lot of pressure in training and they're used to that.
"The World Cup will be a totally different tournament. It's a one-off game when you get to the knockout stages. We'll prepare for the World Cup and hope that we qualify for the quarter-finals."
Richie McCaw captained the visitors for the 100th time - the first player to do so for any nation - and he too felt New Zealand had things under control.
"You've got to keep believing," he said. "It wasn't as if we were under the pump. We just had to hold the ball. Once we did that, we managed to get on top.
"It was important to finish off the year with a performance that we can sit back for a month and be proud of. I'm proud every time I get to lead this team."
Wales coach Warren Gatland added: "I'm really proud of the commitment and performance. It's disappointing but I can't fault the effort. They're the best team in the world because they played for 80. That's the next step for us."