Martin Guptill's masterclass and Finn Allen's ferocious knock had already put New Zealand on top before Todd Astle and Tim Southee ran through Bangladesh's batting line-up to help the hosts win the final T20I by 65 runs in Auckland on Thursday.
Some sensational hitting from the New Zealand openers powered them to 141/4 after the game was reduced to 10-overs-per-side. Bangladesh was then restricted to 76 all out, giving the hosts a fine series sweep.
Chasing 142 for a win in the dead rubber, Bangladesh never looked comfortable as they lost two wickets in the first over, thanks to brilliant bowling from skipper Southee.
Mohammad Naim did play his shots but his stint at the crease was so short that Bangladesh gave up any hope they had before starting the chase.
With Naim's wicket in the fourth over, Astle ran through the Bangladesh middle-order not allowing any batsman to get to the double-digit mark as he finished with four scalps.
Asked to bat first, New Zealand got off to a flying start as both Guptill and Allen unleashed a range of shots right from the word go.
The power-hitting was started by Guptill and Allen joined the party later as New Zealand raced to 43 after the third over. The duo continued their onslaught and a dropped catch by Soumya Sarkar in the fourth over only added insult to the injury.
Bangladesh got the first breakthrough when Mahedi Hasan dismissed Guptill in the sixth over but till then the right-handed opener had already done the damage with his 19-ball 44.
With four overs left and nine wickets in hand, Allen whacked every possible ball which came in his slot to smash the joint-fastest fifty for a New Zealand batsman in just 18 balls.
Bangladesh did dismiss Glenn Phillips, Allen, and Daryl Mitchell in the subsequent overs but couldn't stop the Kiwis from putting 141 runs on board.
Brief Scores: New Zealand 141/4 in 10 overs (Finn Allen 71, Martin Guptill 44); Bangladesh 76 (Todd Astle 4-13, Tim Southee 3-15)