He tore through the top of the West Indian innings, with wickets in his first, second, third and fifth overs to have the tourists reeling at 52 for four.
Kyle Hope, Evin Lewis, Shai Hope and Shimron Hetmyer fell in different ways to Boult – bowled, caught hooking, caught off a skier behind the stumps and caught at slip - who had a spell with figures of 6-1-29-4.
Speester Lockie Ferguson followed that with two wickets in consecutive balls, Jason Mohammed unable to control a sharp lifter and popping a return catch, and Rovman Powell losing his off stump.
Boult then finished the innings with the wickets of Ashley Nurse who top scored with 27, and last man Shannon Gabriel, whom he dismissed with his final ball of the innings.
Ferguson took three for 17 off his four overs.
The final game of the series, at the same venue on Boxing Day is now academic in terms of the three-game rubber and today's result leaves the Windies winless on the tour.
On a ground they are unbeaten in their previous six one-dayers, New Zealand were sent in and finished the innings impressively to push past 300.
Lefthander Henry Nicholls turned in a breezy performance in the closing overs to reach his highest one-day score, an unbeaten 83 off 62 balls.
New Zealand began with a hiss and a roar, as lefthanders George Worker and Colin Munro backed their century first wicket stand in Whangarei last Wednesday with another 50 today in 40 balls before Munro departed.
He had taken a six in consecutive overs from Sheldon Cottrell and Jason Holder before he tried for another hefty blow and was well caught by Mohammed running across to wide mid on.
Neil Broom, brought in for the last two games of the series, struggled to get going, save a top edged hook for six. He was well caught at second slip by Holder, but Worker got to his second half century of the series.
At 58, he casually pulled Ronsford Beaton to fine leg where Powell took the catch, giving Beaton his first ODI wicket in his second game.
Captain for the day Tom Latham got to 20 off 34 balls and Ross Taylor completed his seventh 50 of the calendar year, to go with two centuries, before being caught behind.
Nicholls used the DRS successfully to overturn an lbw decision against him and then went on to his third ODI half century, and with Todd Astle put on a rollicking 130 for the sixth wicket, a record against the West Indies.
Nicholls plundered 6,4,6 in successive Gabriel deliveries in the 48th over which cost the Windies fast bowler 22.
Nicholls was inventive in his strokeplay and Astle proved a good foil and when he swung Powell for six over fine leg it brought up the New Zealand 300.
The batsmen punched 58 off the last five overs to provide a sting in the final stages.
Cottrell finished with three for 62 while Holder took two for 52.
