The White Ferns passed 400 for the second straight game over Ireland before winning their second ODI by a staggering 306 runs.
New Zealand didn't quite match the heights of the 490 they scored in the opening game, being bowled out for 418 overnight in Dublin. They knocked the Irish over for 112 for another convincing win.
Sophie Devine blasted the fastest ODI century by a New Zealand woman, scoring 108, her fourth ODI century, from 61 balls including 13 boundaries and six sixes.
Devine bettered the previous record by 14 deliveries and is second only to Meg Lanning's 50-ball ton for the fastest in world cricket.
Opening New Zealand bowlers Holly Huddleston and Lea Tahuhu claimed a pair of wickets each, alongside braces for spinners Anna Peterson and Amelia Kerr, as the hosts were bowled out in the 36th over.
Earlier, Maddy Green backed up her maiden century with a polished 35-ball fifty, while stand-in captain Amy Satterthwaite chipped in with 48, alongside handy contributions by Anna Peterson (46) and Bernadine Bezuidenhout (43).
The final game of the series is at Clontarf on Wednesday.