The victory ensured the All Blacks completed a clean sweep over Stuart Lancaster's side and they also equalled the record of 17 consecutive Tests wins by a top-tier nation.
Winger Julian Savea and halfback Aaron Smith both scored two tries apiece as the world champions carved up England in the opening 40 minutes at Waikato Stadium to take a 29-6 lead into half-time.
Savea went on to complete his hat-trick in what was a much more dogged second half that began with England winger Marland Yarde scoring his side's only try.
"The first-half performance was pretty special and really won us the game," Hansen said. "England showed their fighting spirit and came back in the second half. It was a seven-all draw with that late try from us.
"The second half wasn't what we wanted. But again throughout the series we've had a lot of things chucked in front of us and challenges we've had to deal with and the second half was another one of those occasions."
Captain Richie McCaw struggled to explain why they had gone off the boil in the second half.
"I'm not sure to be honest. You've got to pay respect to England. They got out to a good start in the second half. We made a couple of mistakes and we were behind our try-line," he said.
"We talked at half-time about wanting to do that to them. They kept playing and we just went a bit hesitant. We didn't get our hands on the ball for quite a period and a bit of frustration came in because we just didn't get to build any pressure. "
Hansen paid credit to England, who had lost the previous two tests by five points and one point respectively, despite making wholesale changes to their side each week as a result of players arriving late from domestic cup finals.
"In the past sometimes these June series have been under-rated by it not being the best teams being brought down here," Hansen said.
"But I think England have paid us a massive amount of respect by bringing their best team down and it's made for a wonderful three-match series."
England coach Lancaster lamented the tourists' lacklustre first 40 minutes and conceded that the better side had won.
"We're disappointed with our first-half performance," he said. "I thought we lacked the intensity we had in the previous two games.
"It obviously was an excellent performance particularly in the first half from them and they certainly thoroughly deserved the win today."