Maiden one-day centuries for Devon Conway and Daryl Mitchell have set-up the Blackcaps 164-run win in the final match of the three match series against Bangladesh at Wellington's Basin Reserve.
Jimmy Neesham chimed in with 5/27, while Matt Henry took 4/27 as New Zealand bowled Bangladesh out for 154 after setting 319 for an unlikely victory.
Skipper Tom Latham won the toss and batted on the best batting surface of the series with Martin Guptill (26) and Henry Nicholls (18) adding 44 inside the first eight overs.
But a three-wicket Tigers blitz had the home side on the back foot, reduced to 57/3 after 11 overs.
Latham joined Conway at the crease and the two left-handers set about rebuilding the New Zealand effort on a wicket crying out for a score over 270.
They added 63 in 13 overs before a hard-hit Latham (18) drive was well caught by Mehidy Hasan Miraz in the gully off Souyma Sarkar (1/37).
Enter Daryl Mitchell, the Cantabrian power-hitting right-handed batsman, who like Conway was playing just his third ODI.
Mitchell's aggressive approach brought the best out of Conway who reached his half-century from 52 balls. Mitchell raised his bat for a first ODI 50 in 63 balls before the pair let loose.
Conway hit 17 boundaries on his way to his ton as he and Mitchell plundered a 159-run partnership in 147 balls.
Bangladesh were their own worst enemies, dropping four catches and were also guilty of several sloppy fielding mistakes that gifted runs to the NZ side.
Conway finally fell for a 100-ball 126 with 16 balls left in the innings.
Mitchell took over from that point, and smashed 17 runs off the final over to reach his century off the final ball of the innings as the Blackcaps posted 318/6 in their allotted overs.
Bangladesh needed to be close to perfect in their run chase, but were 26/3 after seven overs.
Trent Boult's one-handed grab at fine-leg the highlight as Henry claimed all three scalps in an excellent opening spell of 3/18 from seven overs.
Wickets continued to fall with Neesham claiming two in his fourth and eighth overs, while Kyle Jamieson was back to his best, taking 1/30 from an eight-over spell.
Mahmud Ullah was the only bright spot for the tourists, hitting 76 (73) including six fours and four sixes.
The team's head to Hamilton for the first of three T20s o Sunday.