Cullen and O'Hara lay down markers
European U21 Championship: Ireland 0 Norway 0
Ireland continued their unbeaten start to the campaign but were left ruing a couple of late chances wasted in Tallaght.
In a cagey encounter, QPR striker Reece Grego-Cox somehow stabbed his shot wide with 10 minutes left after goalkeeper Sondre Rossbach parried Danny Kane's shot straight into path. And, then, clubmate Ryan Manning came close to preserving Ireland's 100pc record five minutes later when his free-kick forced Rossbach into a one-handed save.
Following back-to-back victories over Kosovo and Azerbaijan, Noel King stuck with the same side and they impressed before the watching Martin O'Neill and Roy Keane - particularly West Ham's Ross Cullen, who is currently on loan with Bolton Wanderers.
Norway's Martin Odegaard ran the show in the first half but he met his match in the form of Ireland goalkeeper Kieran O'Hara.
The stopper spent Tuesday training with the senior squad and O'Neill and goalkeeping coach Seamus McDonagh couldn't have been anything but impressed as they observed from the stand.
Henrik Bjordal's back-flick on 25 minutes gave Thorsby a clear sight on goal but O'Hara made the save.And he came to Ireland's rescue again in first-half stoppage time to deny Odegaard.
It was a different story after the break as the Irish upped the tempo without converting some gilt-edged chances.
"If the game had gone on another ten minutes, I think we might have won it," said King, whose team face Israel on Monday. "It's a bit disappointing but not really when I think of the effort and commitment."
IRELAND - K O'Hara (Man United); C Whelan (Liverpool), R Sweeney (Bristol Rvs), S Donnellan (Walsall), D Kane (Huddersfield); D Rice (West Ham), J Cullen (Bolton Wds); H Charsley (Everton), R Manning (QPR), R Curtis (Derry City); R Greco-Cox (QPR). Sub: C Ronan (Wolves) for Manning (89 mins).