New Zealand appeared in command leading 41-20 with a 12 minutes remaining.
However, Wales launched a furious rally and converted tries to replacements, Steffan Emanuel and Macs Page, shrinking the deficit to seven with a minute left.
New Zealand dispatched the restart deep inside the Welsh 22 where it was caught by talisman No.8 Morgan Morse. Astonishingly Morse kicked the ball into touch and New Zealand secured the lineout and terminated time.
Lineout and counterattack were essential ingredients in New Zealand’s success. New Zealand poached several Welsh throws, often thwarting potentially ominous situations. Despite making more tackles than Wales, New Zealand’s attack flowed smoothly.
New Zealand opened the scoring after eight minutes when halfback Dylan Pledger intercepted from halfway when New Zealand was outflanked three on two.
A failure to secure the restart cost New Zealand points. Wales built momentum and fullback Huw Anderson catapulted through three tacklers.
New Zealand hasn’t won the championship since 2017 with stifling lineout drives so often kryptonite in the barren tenure. A penalty try with centre Aki Tuivailala and winger Frank Vaenuku joining a maul would have been satisfactory for the coaching staff.
Second-five and vice-captain Xavi Taele was possibly New Zealand’s best. Taele carried a dozen times, made the most tackles by a back with nine, and scored two tries. The first was a javelin-like run to the line to make it 24-8.
Four minutes after the interval Tuivailala delivered a wide pass to Taele who fended off Harri Wilde with complete disdain and gracefully glided free.
New Zealand’s lineout proved a trump card again when a dummy jump left Tai Cribb unattended at the front and Bason provided a gift-wrapped throw.
Wales rallied with second five Louie Hennessey to the fore. The Bath product with peroxide hair scored two tries; his first with a brutal 25m bust to make it 36-20.
Xavier Tito-Harris missed selection for the All Blacks Sevens Olympic squad. He showed his future remains prosperous by scoring a try where he and replacement hooker A-One Lolofie combined 50m down an A-One highway.
New Zealand made (128-115) and missed (29-22) more tackles than the Welsh. No.8 Johnny Lee topped the individual tackle count with 20. Locks Liam Jack (12) and Tom Allen (10) were busy and openside Matt Lowe had nine tackles and a few key turnovers.
New Zealand’s next match is against defending champions France who defeated Spain 49-12 in their first fixture.
New Zealand Under 20: 41 (Dylan Pledger, penalty try, Xavi Taele 2, Tai Cribb, Xavier Tito-Harris tries; Rico Simpson 3 cons, pen) Wales Under 20: 34 (Huw Anderson, Louie Hennessey 2, Steffan Emanuel, Macs Page tries; Harri Wilde con pen, Harri Ward 2 con) HT: 24-13