The four-wicket win gave New Zealand the Twenty20 series 2-0 to go with their 2-0 win in the Tests. The one-day internationals were shared 2-2, the West Indies’ only success on their six-week tour.
After New Zealand won the first Twenty20 by 81 runs, they were struggling at 79-5 in the second match before a 68-run partnership between Ross Taylor and Luke Ronchi turned the innings around.
Taylor played the anchor role with 39 off 41 balls while Ronchi belted an unbeaten 51 off 28 deliveries in an innings that included four fours and two sixes.
The pair were particularly harsh on West Indies skipper Dwayne Bravo in the 15th over when they took 17 runs to reduce the target from 54 off 36 balls to a more manageable 37 off 30.
They then took 15 off the 17th over by Jason Holder and although Taylor gave his wicket away with a mistimed slog-sweep to Chadwick Walton at deep midwicket New Zealand were then in a position to coast to victory.
The outcome could have been different had the West Indies been more alert with their fielding.
Jesse Ryder was dropped twice as he raced to a quick 23 in nine balls, and Brendon McCullum received a life on his way to 17.
But the biggest bungle was missing two chances to remove man of the match Ronchi on the first ball he faced.
Andre Russell dropped a caught and bowled opportunity and when Ronchi scampered through for a quick single Tino Best was astray with his run out throw at the stumps.
The West Indies, who won the toss and elected to bat first, appeared to have lost their way when reduced to 67-4 in the 11th over before Denesh Ramdin and Andre Taylor breathed life into their innings.
They put on 70 for the fifth wicket which ended when Fletcher (40) opted to sacrifice himself after he and Ramdin ended up at the same end in a running mix up.
Ramdin carried on through to the end to be unbeaten on 55 off 31 balls in an innings which included three sixes and three fours.