New Zealand chased 217 to win the second match by three wickets with 71 balls left at Malahide.
Bracewell took two wickets for 26 with the ball and made it 42 with the bat, backing up his heroic performance in the first ODI.
New Zealand took full advantage of the difficult hitting conditions to get Ireland all the way in front of 216, with Matt Henry, Jacob Duffy, Bracewell, Mitchell Santner and Glenn Phillips sharing the spoils in a dominant bowling performance.
Ireland did well to get past the 200, thanks in large part to George Dockrell’s 61-ball 74 and Mark Adair’s unbeaten 27 from 15 balls.
Adair then got Ireland off to a stunning start with the ball, claiming Martin Guptill and Will Young for ducks with his first two deliveries.
But Finn Allen and Tom Latham then laid the groundwork for the New Zealand pursuit, as both made half a century.
Still needing a cameo from Bracewell, the Black Caps took up the challenge again, taking the win and series in style with a six down the middle.
Latham was pleased with the performance and praised the bowling unit.
“Winning the toss was crucial and although we did, we put the ball in the right areas,” the skipper said after the game.
“The guys at the top, Matt Henry and Jacob Duffy, set the tone for us by getting some early wickets, which is always important in that power play. And of course the ball was spinning too and I thought the spinners – all three of them – did a fantastic job. To narrow them down to 216 was excellent.”
Latham said Allen’s 60 runs from 58 balls after losing two early wickets were crucial in the chase.
“Obviously the bat had a shaky start but I thought the way Finn came out and played was excellent. He absorbed a little pressure and then put it back on them.
“It was probably similar to those first innings where we couldn’t quite get those partnerships together, but we eventually managed to cross the line.”
The final ODI of the series is on Friday night before three T20s against Ireland start next Tuesday.