Sergio Aguero made an immediate impact on his return to action as Atletico Madrid breathed fresh life into the defence of their Europa League crown at the expense of Rosenborg tonight.
The Argentina striker had not played for Atletico for almost a month due to injury and started tonight on the bench, but he was thrown into the action in the 65th minute and within 60 seconds of his arrival he doubled the lead given to the Rojiblancos by Diego Godin's early header.
Aguero then turned provider in the 77th minute to help Diego Costa add a third goal for Atletico, ensuring a first win of the group stages for Quique Sanchez Flores' men.
The result means Atletico are now third on four points in a tightly-packed Group B, a point behind leaders Bayer Leverkusen, level with Aris Thessaloniki, and a point above Rosenborg.
The defending champions had looked in danger of a shock early exit from the competition after losing away to Aris and drawing at home to Leverkusen, but they were quickly in the ascendancy at the Vicente Calderon tonight after going ahead in the 17th minute.
Jose Antonio Reyes, who played a key part in all three goals, chipped the ball into the area and centre-back Godin - who was at Villarreal last season when Atletico were winning the Europa League - sent a glancing header past Rosenborg goalkeeper Daniel Orlund.
The Norwegian visitors, who started the game in second place in the pool, tried to rally and Markus Henriksen saw his low shot saved by stand-in Atletico goalkeeper Joel Robles, who had taken over from David de Gea.
Orlund then did well to block a Costa effort at point-blank range before Rosenborg came agonisingly close to equaliser on the stroke of half-time when Morten Moldskred hit the post.
That was a big let-off for Atletico, who were finding it tough to get that all-important second goal.
However, that all changed after Aguero was sent on in place of Diego Forlan just after the hour.
Aguero had barely stepped foot on the pitch when he was presented with a shooting chance following Reyes' pass into the area, but there was no sign of rustiness as he coolly slotted past Orlund.
That was the breakthrough Atletico desperately wanted, and they added a third goal for good measure 13 minutes from time following a clinical counter-attack.
Joel's quick throw-out was picked up by Reyes, who progressed deep into Rosenborg territory before feeding the ball to Costa, who then played a clever one-two with Aguero before heading the 22-year-old's lofted return pass beyond Orlund to seal the victory.