After trailing 12-0, New Zealand piled on 38 unanswered points, winning the second half 31-12.
New Zealand started brightly enough with relentless attack in the first ten minutes. Ireland’s defense was initially dogged and their attack was just as clinical.
With their first entry inside the New Zealand 22, Ireland scored a try with robust carries and changes in angles seeing halfback Oliver Coffey sneak over.
It was a messy spectacle with both teams lacking accuracy. That changed in the 32nd minute when Irish fullback Ben O'Connor busted down the left wing, dashed 20m, and created a cracking try for first-five Jack Murphy.
New Zealand enjoyed 56% possession and 61% of territory in the first half. Irish openside Bryn Ward was yellow carded and in the 37th minute, New Zealand captain and hooker Vernon Bason charged over, set up by halfback Dylan Pledger.
In the 43rd minute, New Zealand winger Frank Vaenuku was yellow-carded for an indiscretion at the ruck. Instead of imploding, New Zealand roared to life with two spectacular tries.
Bason spotted a hole and surged 30m in a memorable burst and then centre Aki Tuivailala busted and created a try for his midfield colleague Xavier Taele.
“It’s a rare occasion. I saw the hole open and got through. I dived ten metres early,” Bason laughed about his effort afterward.
New Zealand’s bench introduced a vibrance and urgency previously absent. First-Five Rico Simpson was silky and Jeremiah Avei-Collins a wrecking ball. In the 55th minute, Avei-Collins plundered through multiple tacklers to double the Kiwis' advantage.
Vaenuku atoned for his transgression with two tries. A cross-kick from the influential Xavier Taele was caught unmarked and a rebound from an Irish hand was seized upon.
Ireland ended with a flourish, centre Hugh Gavin an eye-catching talent. In addition to 17 tackles, he ran amok close to full-time. Irish loosehead prop Alex Mullan made 18 tackles.
Taele had 17 carries for New Zealand, double the next-highest individual, tighthead prop Jousha Smith who also topped the Kiwis' tackle count with 11.
This was the second time the teams have met in the third place play-off with New Zealand victorious 45-23 in 2014 at Eden Park. Future All Blacks first-five Richie Mo'unga scored two tries.
Ireland’s only victory over New Zealand in nine meetings at this tournament came in the pool stage in 2016 when they won 33-24 in Manchester. Lock James Ryan was man-of-the-match with prop Andrew Porter starring in a dominant scrum. Both players featured in Ireland’s 2022 series win against the All Blacks.
Ireland has won 33 of their 69 tournament matches, New Zealand 56 of 70. New Zealand became the first team to score 400 tries in the U20 Championship when Tuivailala crossed in the 59th minute of the semi-final defeat against France.
New Zealand Under 20: 38 (Vernon Bason 2, Xavier Taele, Jeremiah Avei-Collins, Frank Vaenuku 2; Rico Simpson 4) Ireland Under 20: 24 (Oliver Coffey, Jack Murphy, Ethan Graham, Sean Naughton tries; Murphy 2 con) HT: 7-12