Giovanni Trapattoni's side, who set out on the road to South Africa 2010 against Georgia next month, had to weather a storm both figuratively and literally as the Scandinavians completed their own preparations for the forthcoming qualifiers.
After a slow start the visitors assumed control before the break and took a deserved lead through skipper Robbie Keane's predatory 44th-minute strike.
However, substitute goalkeeper Dean Kiely's error 16 minutes after the break handed defender Tore Reginiussen an equaliser and the Norwegians will feel aggrieved not to have gone on to claim victory after exerting intense pressure for the remainder of the game.
But Ireland managed to hang on to extend their new manager's unbeaten start, while at the same time leaving them in little doubt that there is work to be done before they meet Georgia - wherever that game is played - and, four days later, Montenegro.
Trapattoni voiced the opinion in the run-up to the game that his side and that coached by Age Hareide face similar tests in the World Cup qualifying campaigns, the Irish having to cope with the might of Italy as well as tricky clashes with the likes of Georgia and Montenegro, while Norway take on Holland and Scotland.
With Norway occupying joint 29th place in FIFA's latest rankings - the Republic are 41st - he was confident the test at the Ullevaal Stadium would be a more than useful one before hostilities begin in earnest next month.
In that context, he will have been a happy man at the break having seen his players recover from an uncertain start to dominate despite torrential rain.
The Norwegians' 4-3-3 formation initially caused Ireland problems with central defender Richard Dunne in particular having difficulty even keeping his feet on a sodden pitch.
Shay Given was grateful to see striker Mohammed Abdellaoue lift a 10th-minute shot over the bar after running onto John Arne Riise's pass and rounding John O'Shea.
Riise forced the game's first real save 12 minutes later with a dipping drive which Given claimed low to his right.
However, as the half wore on, it was the visitors who began to control the match with wingers Damien Duff and Aiden McGeady seeing plenty of the ball as Steven Reid and Glenn Whelan held firm in central midfield.
They might have gone ahead on the half-hour when Keane twisted his way into the penalty area and unleashed a firm left-foot shot from a tight angle which goalkeeper Rune Almenning Jarstein did well to turn away.
But with the pressure mounting, the home side eventually cracked a minute before the break.
Norway were still coming to terms with the premature departure of midfielder Fredrik Stromstad when Keane cut inside from the right and fired past Jarstein to claim the 34th goal of his international career.
Given's contribution ended at the break when he was replaced by Kiely, while Blackburn's Morten Gamst Pedersen replaced Daniel Fredheim Holm as Hareide looked to pose a different threat.
But the game was increasingly becoming a lottery with surface water gathering and no sign of the deluge relenting.
A resurgent Norway, however, were enjoying the better of the game for the first time since the opening exchanges, although Riise wasted a good opening when he sliced a 55th-minute shot horribly wide.
The equaliser finally arrived six minutes later when Kiely came for, but missed, Martin Andresen's left-wing free-kick, and when a stunned Kevin Kilbane could only head the ball back across goal, Reginiussen gleefully converted from point-blank range.
The Irish were in some disarray and had Kilbane not thrown himself into the path of Riise's audacious 65th-minute volley, Kiely might have been picking the ball out of his net once again.
Trapattoni opted for a change as the clock ran down when, having already replaced Kevin Doyle with Daryl Murphy, he sent on Stephen Hunt and Stephen Kelly for McGeady and Finnan.
But although the Irish regained a foothold in the game - it took a fine last-ditch interception from Reginiussen to stop Keane collecting Murphy's 86th-minute through-ball - it was the home side who looked the more likely victors.
Riise saw an 89th-minute shot deflected just wide as the home fans rose to their feet, but there was to be no further addition to the scoreline.