Steven Finn cemented his place in the England attack with 3-27 as the Black Caps were skittled out for a mere 185, with Stuart Broad and Graeme Swann chipping in with two wickets apiece.
That left a routine chase for the tourists, and a solid 46 from Alastair Cook set them on their way before a brutal 24-ball 39 from Eoin Morgan helped England wrap up the win with more than 12 overs to spare.
It was a humiliating defeat for New Zealand, who are seen as limited-overs specialists, and former England batsman Robert Key believes this heavy defeat could cause a crisis of confidence in the hosts' dressing room ahead of the opening Test in Dunedin on March 6.
Key told Sky Sports: "It will have shredded New Zealand's confidence. You've got to remember the one-day game is their strongest suit. They just beat South Africa in South Africa so they will be thinking really and truly that this was their big chance of a series win.
"They haven't looked like they've got an answer to the bowling of the England team - most specifically James Anderson and Steven Finn. Potentially without Martin Guptill for the Test series, it's going to be tough for them."
England have the likes of Graham Onions and Chris Woakes pushing for inclusion in the seamer ranks as well as spinner Monty Panesar waiting in the wings while with the bat, youngster Joe Root has made a big impact on tour.
Former England quick Dominic Cork is adamant that injuries to New Zealand's stars can not be covered so easily, and said: "It's part and parcel of why England are so good because they have people to turn to when they have injuries. New Zealand don't have that same depth that we have.
"I just think it's been a solid performance. You've got to remember that a few of these players have been fresh coming from no cricket, and the likes of Trott and Cook have got runs. The likes of Woakes have come in and done very well, too.
"You get the job done, whether it's ugly or not. They've won this series, and the big ask is how quickly can they finish them off in the Test series? You'd expect, on that performance, to beat New Zealand 3-0."
Key added: "In the Twenty20, we saw England throw caution to the wind and really go for it. Eoin Morgan did it to a degree here - he came in and played a cameo innings.
"If you wanted to go hard at the ball, there was every chance you could score quickly and clear the ropes even on mis-hits, but the fact is that England never had to use that intent. New Zealand on the other hand, could have done. They didn't show much intent at all."
The success of the ODIs throws up some welcome selection problems for England, with Root named in the Test squad and expected to be integrated into the XI sooner rather than later.
Key was quick to praise England's current ODI glovesman too, saying: "Jos Buttler had a quiet time with the bat as he didn't get too many opportunities but he's gone unnoticed with the gloves which I think is a really good thing.
"It was a big moment for him when he was chosen as the wicket-keeper ahead of Jonny Bairstow and Craig Kieswetter and he's had a really good time of it with the gloves.
"I think with regards to the top of the batting order it will be Nick Compton to open and Root will go in at number six and the opening spot will be Compton's to lose."
Cork added: "There'll be a big talking point as to whether Stuart Broad will make the side. I think he should play, and then you've got the likes of Graham Onions and Chris Woakes if needed. I think Broad will be in at eight, Swann nine, Finn ten, Anderson eleven and England will win 3-0.
"I don't think Monty Panesar will play in New Zealand but he's there just in case. England have a strong squad."