New Zealand 360 for 6 (Guptill 115, Nicholls 79, Little 2-84) beat Ireland 359 for 9 (Stirling 120, Tector 108, Henry 4-68, Santner 3-71) by one run
Dublin: New Zealand sealed a 3-0 series whitewash over Ireland thanks to a dramatic one-run victory on Friday.
Martin Guptil's 115 and 79 from Henry Nicholls helped the tourists to an impressive 360-6 at Malahide.
Centuries from Paul Stirling (120) and Harry Tector (108) saw the hosts go close to a first win over the Black Caps.
The Irish hit their highest ODI total but Graham Hume was unable to make three off the final ball for victory.
It is another big disappointment for Ireland in the series after losing the opener by one wicket when Michael Bracewell hit a record-breaking 24 in the final over.
New Zealand set a daunting target for an Irish side whose previous best ODI score was 331 but the game went down to the wire.
Guptil and Finn Allen (33) laid the foundation for a big score with an opening stand of 78 before Tom Latham added 30.
A partnership of 96 between Guptil and Henry Nicholls (79) was followed by a quickfire 47 by Glenn Philips.
Josh Little took wickets for the Irish, who started their reply with skipper Andrew Balbirnie dismissed for a duck in the first of four wickets for Matt Henry.
It was left to Ireland's top two batters - Stirling and Tector - to take centre stage and they put on a superb 179 for the third wicket.
Tector was was bowled by Mitchell Santner to leave the hosts 310-6 after 43.3 overs and in with a chance to upset the odds.
Ten were required off the final over and then three from the last ball but Hume was unable to connect with Blair Tickner's delivery and a single was not enough as the Irish finished on 359-9.
The teams meet again on Monday in the first of three T20 encounters at Stormont in Belfast.