Lawrie Sanchez's reign as Northern Ireland manager began with defeat by Norway at Windsor Park, although they finally ended their long goal drought.
Northern Ireland, who have not won for 28 months, were 3-0 down at half time.
Morten Pederson marked his debut with a brace and Steffen Iversen got the other to leave the home side stunned.
Northern Ireland got their first goal in 14 games when David Healy headed home but a Keith Gillespie own-goal dashed hopes of a revival.
Norway made the breakthrough after 17 minutes following a mix-up between
goalkeeper Maik Taylor and skipper Aaron Hughes.
They failed to cut out a cross from Thorstein Helstad and Pedersen
blasted the loose ball into the roof of the net.
Norway extended their lead after 35 minutes when Pedersen got his second
goal of the night.
He clipped a superb volley beyond Taylor from an acute angle after Martin
Andresen chipped the ball over the top.
Iversen made it 3-0 to Norway two minutes before the break with his shot going through Taylor's legs.
Northern Ireland's long-awaited goal came on 56 minutes when Healy headed in from a Gillespie cross for his first international goal since October 2001.
It ended a run of 1298 minutes without Northern Ireland finding the target
But, within a minute, Gillespie diverted the ball into his own net after Helstad had fired it into the danger area.
Healy had a chance to get his second near the end but the Preston striker volleyed over.
Northern Ireland: Taylor, Baird, Aaron Hughes, McCartney,
Kennedy (Jones 77), Gillespie (McVeigh 73),
Griffin (Williams 46), Johnson, Michael Hughes, Healy, Smith.
Subs Not Used: Sonner, Whitley, Elliott.
Norway: Myhre (Holtan 70), Andresen, El Fakiri, Hangeland,
Helstad (Hoiland 89), Hoseth, Iversen, Ronny Johnsen,
Riise (Hanstveit 70), Rushfeldt (Haavard Flo 46),
Pedersen (Odegaard 81).
Subs Not Used: Tessem.
Referee: C Thomson (Scotland).