Mike Ruddock's youngsters led 23-21 at half-time with Ross Byrne kicking three penalties and converting a penalty try and an opportunist effort from prop Oisin Heffernan.

But the Baby Blacks dominated both possession and territory after the break and went on to score four more tries through James Tucker, Mitchell Drummond, Richard Mo'unga and Lachlan Boshier.

It was a cruel ending to what was a brave Irish performance, but Ruddock's class of 2014 can still look back on the tournament with immense pride as fourth place is Ireland's best ever finish at a Junior World Championship.

Ireland looked the better organised and disciplined team in the opening 40 minutes in Auckland, getting decent reward for the variation to their play while New Zealand relied heavily on counter-attacking opportunities.

Peadar Timmins, who captained Ireland in James O'Donoghue's absence, and Peter Dooley were the only survivors from last summer's 31-26 loss to the Baby Blacks in France.

Ireland were first to threaten, settling to the task with an impressive lineout maul before Cian Kelleher unfortunately knocked on a cross-field kick from out-half Byrne.

Ross Molony won the first two Irish lineouts and also stole New Zealand's opening throw, but a powerful run from lock Tucker ignited the hosts' attack.

TMO Chris Wratt ruled that Mo'unga's pass to Tevita Li was flat after the dangerous winger had scooted in under the posts. Mo'unga converted for a 7-0 lead.

Byrne snapped back three points with a penalty from inside the 22 and Harrison Brewer combined with the entire back row in a 'choke tackle' which forced a turnover.

A superb spell of attacking, with Junior Player of the Year Garry Ringrose, Kelleher and Ciaran Gaffney threatening out wide, led to Byrne knocking over his second penalty.

Before that Ireland had been a pass or two away from crossing the New Zealand whitewash as Frankie Taggart and Dooley carried with great intent, offering quick ruck ball for half-backs Nick McCarthy and Byrne.

However, the Baby Blacks showed their class on the counter when full-back McKenzie beat Gaffney to a high ball, Li blazed through on the left wing and linked inside with scrum half Drummond who broke Kelleher's tackle to score a seven-pointer.

As the rain began to fall, Heffernan blocked a clearance kick as Ireland exerted more pressure in the hosts' 22 which led to their penalty try, props Dooley and Heffernan earning the plaudits for an advancing five-metre scrum.

Byrne converted to close the gap to 14-13 and Ireland hit the front in the 28th minute thanks to their out-half's third successful penalty, with Tucker sin-binned for infringing at a well-orchestrated maul.

Again though, New Zealand splintered the Irish defence for a try out of nothing. The scoring pass from Mitchell Drummond, at the end of a lightning quick move, appeared to drift forward but Li's second score - converted by McKenzie - was allowed to stand.

The lead changed hands within three minutes as Ringrose carried into the Kiwis' 22, the ball squirted loose and Heffernan got his right shin to it before hacking on with his left boot and gathering to crash over the line past McKenzie.

TMO Wratt confirmed that there was no knock-on from the Lansdowne clubman and Byrne's conversion split the sides at 23-21.

The home side turned down a kickable penalty in the dying minutes of the half and a knock-on spoiled their efforts to run in an injury-time try, as Ireland came off with a two-point advantage.

New Zealand resumed in fine fettle though with Kelleher coming to Ireland's rescue as he ripped the ball free to save a certain try. Tucker and replacement Kyle Harris were then both held up in quick succession.

Ireland's defence continued to hold out until Tucker rumbled over from close range in the 50th minute. McKenzie missed the conversion from the left

The missed tackles were beginning to mount for Ireland, but some clever interplay between the hard-working Brewer and Taggart on the left and a side-stepping counter from Kelleher saw them gain some rare attacking momentum.

Replacement Dan Goggin's well-won turnover and a subsequent kick from Byrne brought Ireland back into the hosts' 22 for the first time in the second half, with 57 minutes on the clock.

However, despite more replacements being introduced, Ireland were running out of steam against an increasingly dominant New Zealand and a yellow card for Kelleher on the hour mark came at just the wrong time - he played the ball from an offside position at a ruck near his own whitewash.

Spirited defence thwarted the Baby Blacks until Mo'unga brilliantly gathered his own chip and passed for his half-back partner Drummond to run in their fifth try of the night. McKenzie converted for 33-23.

Tired bodies meant more space for free-running New Zealand to exploit and winger Vincent Tavae-Aso broke through on the left to put Mo'unga over for a textbook 72nd minute score.

Ireland had more of the play after Kiwi replacement Troy Callander was sin-binned for a high tackle on Kelleher, but their try-line was troubled again by Li before flanker Boshier's 79th-minute try eventually completed the scoring.

NEW ZEALAND U-20: Damian McKenzie; Vincent Tavae-Aso, Anton Lienert-Brown (capt), TJ Faiane, Tevita Li; Richard Mo'unga, Mitchell Drummond; Atunaisa Moli, Hame Faiva, Tau Koloamatangi, James Tucker, Geoffrey Cridge, Tom Sanders, Lachlan Boshier, Matt Peni.

Replacements: James O'Reilly, Scott Mellow, Tim Cadwallader, Troy Callander, Kyle Harris, Josh Renton, Kaveinga Finau, David Kaetau Havili.

IRELAND U-20: Cian Kelleher (Lansdowne/Leinster); Ciaran Gaffney (Galwegians/Connacht), Garry Ringrose (UCD/Leinster), Harrison Brewer (Terenure College/Leinster), Alex Wootton (Garryowen/Munster); Ross Byrne (UCD/Leinster), Nick McCarthy (UCD/Leinster); Peter Dooley (Lansdowne/Leinster), Dylan Donnellan (UCD/Leinster), Oisin Heffernan (Lansdowne/Leinster), Darragh Moloney (Cork Constitution/Munster), Ross Molony (UCD/Leinster), Peadar Timmins (UCD/Leinster) (capt), Rory Moloney (Buccaneers/Connacht), Frankie Taggart (Belfast Harlequins/Ulster).

Replacements: Max Abbott (Cork Constitution/Munster), Denis Coulson (Lansdowne/Leinster), Rory Burke (Cork Constitution/Munster), Stephen Gardiner (Lansdowne/Leinster), Josh Murphy (UCD/Leinster), Ryan Foley (Cork Constitution/Munster), Conor McKeon (Lansdowne/Leinster), Dan Goggin (Young Munster/Munster).

Referee: Alexandre Ruiz (France)

Scorers:

New Zealand: Tries: Tevita Li 2, Richard Mo'unga 2, James Tucker, Mitchell Drummond, Lachlan Boshier; Cons: Damian McKenzie 5

Ireland: Try: Penalty try, Oisin Heffernan; Cons: Ross Byrne 2; Pens: Ross Byrne 3