Finn Allen and Tom Latham scored half-centuries as New Zealand held their nerve to seal a series-clinching three-wicket win against Ireland on Tuesday.

Mark Adair put New Zealand under pressure when he removed Martin Guptill and Will Young with the first two balls of the innings as they chased Ireland's 216 all out.

But Allen's composed 60 ensured there would not be an upset in Malahide as the Black Caps won the series with one game remaining.

Michael Bracewell, Mitchell Santner and Matt Henry each helped themselves to two wickets as New Zealand easily restricted Ireland in the hosts' innings.

It was only George Dockrell's ODI-best 74 from 61 balls and Adair's 27 from 15 balls that enabled Ireland to pass 200.

New Zealand's poor start to their chase was soon forgotten as they composed themselves once Latham (55) joined Allen in earning a half-century.

Tom Latham reacts after scoring his fifty with a six. Photo: Twitter

A middle-order wobble put the result back in doubt until Bracewell translated his fine form with the ball to the bat.

Bracewell's heroics led New Zealand to victory by one wicket in the opening game and his unbeaten 42 carried the tourists over the line again with 71 balls to spare.