Desperately unlucky against a very strong Norwegian side - who have already notched two massive back-to-back 7-0 wins in the group – it was the future Irish stars who started the brighter, pressing high with the two front men proving a handful throughout.
Goals from that front pair of Aidomo Emakhu and Sinclair Armstrong either side of half-time wasn't enough as Norway turned the game on it's head battling back from 2-1 down to win 3-2.
Ireland had the better of the chances in the first half Emakhu slipped Armstrong in first time, before the QPR hitman struck powerfully from the edge of the area straight at Sander Tangvk.
To their credit, Ireland seemed relatively comfortable at times, but in the 20th minute and against the run of play, Halvor Rodolen Opsahl rose highest in a busy area to loop a header high into the side netting to make it 1-0 to the home side.
Jim Crawford's side responded well to the setback and could have been level minutes later when Emakhu cut inside on his right foot and reversed a powerful drive into the bottom corner only to be denied brilliantly again by Tangvk.
The calculated high press finally paid off 10-minutes before the break when the hard-working Millwall man Emakhu nicked the ball again. Sinclair Armstrong picked up the loose ball, and much like the first couple of minutes, drove to goal but this time saw his powerful shot deflected kindly into the path of his strike partner, who applied the finish from close range for a well-deserved leveller.
The intriguing tactical battle continued and just seven minutes after the break Ireland turned the tie on its head with the ex-Shamrock Rovers front two again doing the damage with a razor-sharp one-two.
From the long free-kick, Armstrong rose highest to flick the ball onto Emakhu, who quickly then returned the ball into his path, before the big number 9 finished superbly first time into the bottom corner.
Just minutes after his introduction, Johnny Kenny was desperately unlucky not to make it three showing great strength to hold off and spin his marker before smashing the ball across goal deflecting off keeper Tangvk who bravely stood big to make the save.
Ireland were made to rue the miss when, with twenty minutes remaining, the home side managed to get themselves back on level terms from the spot through Kristian Arnstad. Leo Hjelde was felled in the area from a dangerous looking corner and the Anderlecht midfielder, Arnstad, made no mistake from 12-yards.
Disaster struck minutes later when substitute Lasse Nordas finished brilliantly from close range, lifting the ball high past the helpless Josh Keeley to put his side back in front.
Unfortunately, time just ran out as the visitors desperately tried to get themselves level, raining corner after corner but failed to scrape an all important, and probably deserved equaliser.
Next up for the Under-21s is a clash against Italy in Turner's Cross Stadium.
Speaking after the game: "We've known from the very start working with this group there is unbelievable character here. We've had so many challenges up to now there's no doubt the group in there will learn.
"To come to their patch and give them a hell of a game is a small consolation. We can't feel sorry for ourselves, we've got a massive game coming up against Italy in Turner's Cross. It's about getting ourselves ready for that game from now."
Norway: Sander Tangvk; Eskil Edh (Fredrik Sjovold, 57’), Leo Hjelde, Halvor Rodolen Opsahl; Fredrik Oppegard, Christos Zafeiris, Odin Thiago Holm (Lasse Nordas, 57’), Kristian Arnstad, Tobias Gulliksen (Daniel Karlsbakk, 57’); Joel Mugisha, Isak Hansen-Aaroen
Ireland: Josh Keeley; Sam Curtis, Bosun Lawal, Anselmo Garcia MacNulty, Connor O’ Riordon, Sean Roughan (Tayo Adaramola, 83’); Matt Healy, Baba Adeeko (Ollie O’Neill, 83’), Kian Leavy (Killian Phillips, 70’); Sinclair Armstrong, Aidomo Emakhu (Johnny Kenny, 62’)