Chelsea sealed qualification for the knockout phases of the Champions League on Wednesday evening with a scintillating performance at Rosenborg.

The Blues were superb from first to last, opening the scoring inside five minutes and never looking back, as Didier Drogba bagged himself two goals, while Alex and Joe Cole completed the scoring.

The resounding win guarantees Chelsea top Group B, and progress to the knockout stages in February.

It was a bitterly cold night inside the open-cornered Lerkendal stadium, which made for difficult conditions in which top football could be played. Indeed the Norwegian league season was concluded in late October, and so competitive games in these parts are rare in late November.

Chelsea arrived expecting a difficult game, but both Carlo Cudicini and Avram Grant had maintained the weather would have no impact on the outcome of the game, and so it proved as Rosenborg were brushed aside.

The Blues began the game in perfect fashion, as Didier Drogba returned from injury to open the scoring in the seventh minute, by which point the lead could already have been obtained.

Drogba, had almost given us a first minute lead, but a combination of defender and goalkeeper forced him to shoot wide when off balance.

Three minutes later Drogba came close again, turning his marker Vidar Riseth and unleashing a powerful long-range drive that whistled wide of the hosts' net.

With little over five minutes on the clock, Essien missed Chelsea's third opportunity. An Ashley Cole-led counter attack culminated in the Ghanaian shooting over from Drogba's nod down. The knee injury that kept Drogba from playing against Derby showed no signs of holding him back.

By the eighth minute, Chelsea's obvious early superiority was confirmed. Once again it was Drogba in the thick of things, firing home the rebound after Joe Cole's enterprising run and shot had been parried by Rosenborg keeper Lars Hirschfeld.

Chelsea's refusal to be knocked back by the chill in the air clearly surprised Rosenborg, who were slow coming out of the traps. Their first goal bound effort came courtesy of Slovak midfielder Marek Sapara, whose bouncing shot was gathered at the second attempt by Carlo Cudicini, who continued to deputise for the injured Petr Cech.

By the 20th minute, the lead was doubled as Drogba grabbed his fourth Champions League goal this season. The hard work was done by Essien, whose terrier-like spirit in the middle won the ball, and Wright-Phillips, who was as fleet-footed and skilful as anyone has seen since his arrival at the Bridge.

That pair combined, and the ball dropped for the Ivorian, who expertly dispatched his finish with the minimum of fuss. Two up inside 20 minutes was as much as could have been hoped for before kick-off.

The Blues continued to excel, dominating all areas of the field, and rarely looking threatened. Lampard almost increased the lead to three before the half-hour mark, serving up the most delicious of chips that had Hirschfeld back pedalling to palm the ball out.

Five minutes later the Canadian stopper was called into action again, stopping a Drogba drive after Lampard had made space for the forward.

To their credit, Rosenborg's enthusiasm showed no sign of waning, but by 39 minutes, the game appeared over.

A foul on Joe Cole allowed Alex the opportunity to unleash a trademark free-kick, but unlike the rocket at Middlesbrough, this goal was a rather tame effort, deceiving Hirschfeld, and sealing Chelsea's progression into the knockout stages.

Before half-time Alex almost doubled his own tally, heading Lampard's corner toward the bottom corner. Only Hirshfeld's desperate lunge kept the ball out.

With such a margin at the break, it could be expected that the Blues would take a collective foot from the pedal, but this didn't appear to be the case, as yet more attacking football flowed.

Essien again tested Hirschfeld from range, while Wright-Phillips saw his shot come back off the post after combining with the ever-available Drogba.

Rosenborg continued to probe the Chelsea defence, but it was the visitors who continually penetrated. Essien, who by now deserved a goal, had a shot hacked off the line shortly before the hour mark.

As the game threatened to ebb away, Sapara brought it back to life. He curled a free-kick towards Cudicini's top corner, forcing the Italian into a fine acrobatic save to maintain his clean sheet.

With an eye on Saturday's league game with West Ham, Avram Granted opted to withdraw Drogba, Wright-Phillips and Lampard, replacing them with Andriy Shevchenko, Salomon Kalou and Claudio Pizarro.

It only took four minutes for the lead to increase, Shevchenko involved as Joe Cole netted from close range, having won possession out on the left flank. A minute later, the Ukrainian should have made it five, dragging a low shot wide after making space for himself inside the box.

Rosenborg still wouldn't lie down, and former Spur Steffen Iversen headed wide from close range, while Alexander Tettey fired wide. Sub Didier Konan Ya, who just like Drogba hails from Abidjan, also went close.

It was another sub who was next to miss the target, Kalou screwing wide after he had twisted his marker inside out. A better option would have been to square to the onrushing Cole or Shevchenko.

In the closing minutes Kalou almost did find the net. Following a passing move that involved most of the Chelsea side, he curled a shot just over the bar. A minute later Belletti got in on the act, finding space to run into and shoot, but his effort also evaded the target.

There was still time for Cudicini to pull off another superb save, pushing Konan Ya's drive wide.

That was the final action of an entertaining game that had seen Chelsea at our best, executing the type of passing football Avram Grant demands.

After sealing qualification on a cold night in Trondheim, Chelsea's Champions League campaign is just hotting up.

Rosenborg (4-3-1-2) Hirschfeld; Stoor, Kvarme, Riseth (c), Dorsin (Basma 85); Skjelbred, Traore (Strand 55), Tettey; Sapara; Koné (Konan Ya 62), Iversen.

Chelsea (4-3-3): Cudicini; Belletti, Alex, Terry (c), A Cole; Essien, Makelele, Lampard (Pizarro 75); Wright-Phillips( Kalou 68), Drogba( Shevchenko 68), J Cole.

Goals Drogba 7, 20 Alex 39 J Cole 72

For highlights of today's game, log on to Chelsea TV Online, or alternatively for the full 90 minutes, tune in to Chelsea TV, from Thursday at 11pm.

By Andy Jones