Mitchell Santner's career best ODI figures set up a 51-run victory for New Zealand in their opening tri-nation series game against Ireland in Malahide.
Santner finished with five for 50 as Ireland were bowled out for 238 in the 46th over, the hosts losing their last five wickets for 26 runs.
Niall O'Brien provided valiant resistance as Ireland threatened an upset, but once he became the eighth man out for 109 the game was up for the home side.
O'Brien's first ODI century came off 125 balls, with nine fours and five sixes, but the only batsmen to stay with him were Andrew Balbirnie (36) in a third-wicket stand of 86 and Gary Wilson (30) in a fifth-wicket partnership of 75.
Scott Kuggeleijn, on his ODI debut, removed Ireland openers William Porterfield and Paul Stirling in his first three overs and returned to have Wilson caught in the covers by Ross Taylor to spark the Ireland collapse.
The other Blackcaps debutant, Seth Rance, finished the match with his first wicket, trapping last man Peter Chase leg before.
Ireland also gave a debut to off-spinning all-rounder Simi Singh, who came in for Stuart Thompson in the only change to the team that played Bangladesh in the opening game of the series on Friday.
Neil Broom was the star of the New Zealand innings, hitting 79 from 63 balls with nine fours and a six, to build on half centuries from Ross Taylor (52) and George Worker (50).
Porterfield won his second successive toss but it was New Zealand opener Luke Ronchi who got the innings off to a fast start with 37 from 26 balls, before he got a leading edge to a pull shot and was caught at point.
The wicket-taker was Barry McCarthy, who can surprise batsmen with his pace, and as a result he has a habit of taking early wickets. This one came from his 11th delivery and three balls later he had his second when captain Tom Latham was caught behind for 15 to leave New Zealand 55 for two in the 10th over.
Worker and Taylor, however, were untroubled in the next 20 overs as they added 86 for the third wicket. Worker, in only his third international, was the more patient while Taylor scored at a run-a-ball.
Both reached their 50s, but both were out immediately afterwards, Taylor caught by the Irish captain at point and Worker, whose half-century took 88 balls, with just three fours, caught at deep mid-wicket.
Broom however ensured a big finish for New Zealand, who scored 130 off the last 15 overs.
The pick of the Ireland bowlers was Kevin O'Brien with one for 46 and although George Dockrell, the only spinner used, finished wicketless, he conceded only 42 runs.
Peter Chase could not continue his good early season form, going for 74 runs and taking his only wicket in the last over.
NEW ZEALAND: 289 for 7 (Ronchi 37, Worker 50, Taylor 52, Broom 79; Murtagh 2-62, McCarthy 2-59)
IRELAND: 238 all out in 45.3 overs (O'Brien 109, Balbirnie 36, Wilson 30; Kuggeleijn 3-41, Santner 5-50)
Result: New Zealand won by 51 runs.