Diarmuid Kearney reports from Turner's Cross
First-half goals from Jonathan Levi put Rosenburg in the driving seat as they take the advantage back to Norway following their Europa League third qualifying round victory over Cork City at Turner's Cross.
City remained unchanged from the side that ran out 2-1 winners over Waterford in the league last time out, while Rosenborg made one change with Levi coming into the starting lineup, the only change from the scorless draw with Celtic.
The Leesiders started the brighter of the sides. An early chance for Karl Sheppard was dealt with before their best chance came in the just the fifth minute, when a free kick was whipped in but the header went over the crossbar.
Levi came closest for the visitors in the early stages as he hit a low driven shot from outside the area but Mark McNulty smothered any danger in the City goal.
John Caulfield's charges should have been in front after the 10th minute mark.
A glorious ball sent in to Barry McNamee but his shot was scuffed off the defender and cleared away.
Moments later McNamee could have found the net again.
Given the ball in space by Garry Buckley on the edge of the area, his left-footed curling effort stung the palms of Andre Hansen in goal and almost ended with Karl Sheppard having an opportunity to tap in the lose ball, but the danger was cleared.
The Leesiders had much the better of possession in the opening quarter of an hour but failed to make their chances count, with another shot going well wide this time from skipper Conor McCormack.
Against the run of play the visitors found the net in the 22nd minute. Levi received a pass and broke into the box before dispatching a low shot under McNulty into the Cork goal.
It could have easily been two for Rosenborg shortly after when a defensive lapse in concentration allowed Levi to once again run through into the area but his shot went straight at McNulty.
City looked to have found the equaliser shortly after the half-hour but Garry Buckley's fizzed shot across goal was just about dealt with by Hansen after striking the post.
The Leesiders stayed on the front foot and an effort from distance by Sheppard just flew past Hansen's upright in the Rosenborg goal.
Shortly before the half time interval Rosenborg doubled their lead.
Some quick precise passing fed Levi on the edge of the box and his shot managed to find its way into the net via the post, leaving McNulty no chance in the Cork goal.
Like the opening half, the Leesdiers dominated the early stages of possession after the break but were still unable to find any opening in the Rosenborg defence.
The introduction of Kieran Sadlier at half time was working wonders for the City attack and he almost pulled one back in the 66thminute as his effort just went over the bar.
City could have halved the deficit in the 68thminute but Rosenborg netminder Hansen pulled off a phenomenal save to stop a Sadlier free kick from nestling in the bottom corner.
Despite trailing with just 20 minutes left, City were bombarding the Rosenborg defence in search of a crucial goal. Gearoid Morrissey hit one from the edge of the box but it went just wide.
Rosenberg could have sealed the tie in the 73thminute. Nicklas Bendtner swung a ball in that Lovi headed toward Mike Jensen but the captain's shot somehow found its way wide.
It finished a disappointing night for the home side as Rosenborg ran out convincing and deserved winners on the night.
Cork City: Mark McNulty, Steven Beattie, Jimmy Keohane, Damien Delaney, Conor McCormack (Gearoid Morrissey 60), Shane Griffin, Barry McNamee (Kieran Sadlier 46), Sean McLoughlin, Graham Cummins, Karl Sheppard,(Ronan Coughlan 71), Garry Buckley.
Subs not used: Peter Cherrie, Alan Bennett, Aaron Barry, Josh O'Hanlon.
Booked: Garry Buckley (55), Sean McLoughlin (62), Ronan Coughlan (84).
Rosenborg: Andre Hansen, Vegar Hedenstad, Even Hovland, Tore Reginiussen, Birger Meling, Mike Jensen, Marius Lundemo, Anders Trondsen (Olaus Skarsem 85), Jonathan Levi, Nicklas Bendtner, Alexander Soederlund (Erik Botheim 75).
Subs not used: Matthias Vilhjalmsson, Alex Gersbach, Eriend Reitan, Arild Ostbo, Besim Serbecic.
Booked: Andres Trondsen (57) Even Hovland (66), Tore Reginiussen (71).
Referee: Petr Ardeleanu (Czech Republic).
Extratime.ie Player of the Match:Jonathan Levi (Rosenborg).