Match ends, Roma 1, FC Bayern München 7.
Bayern Munich stunned Roma with their biggest ever away win in Europe to maintain their 100% record in Group E.
Arjen Robben beat Ashley Cole to curl a stunning opener and Mario Gotze combined with Thomas Muller to score.
Robert Lewandowski's header and Robben's powerful finish arrived before Muller's penalty made it 5-0 with just 36 minutes on the clock.
Gervinho headed a consolation but Franck Ribery and Xherdan Shaqiri struck as Bayern reached nine points.
They are now five points clear of Roma and seven ahead of Manchester City, who earlier threw away a two-goal lead to draw 2-2 at CSKA Moscow.
A win when the Italian side visit the Allianz Arena in two weeks will guarantee Bayern's progress to the knockout stages, but it is the manner of this win which will worry Europe's elite.
Roma sit second in Serie A and have lost just once at home since the start of last season, but they were demolished by slick attacking football at the Stadio Olimpico.
Robben teased former Chelsea and Arsenal full-back Cole - who was substituted at half-time - before bending his opening goal beyond the dive of Morgan De Sanctis and Gotze's finish from 18 yards swiftly followed.
Lewandowski powered Juan Bernat's cross home, Robben ran clear of the lacklustre home defence to blast the fourth and Muller's penalty came after a cross was handled in the penalty area.
|Close but not perfect|
|Prior to Gervinho's goal, Bayern had not conceded for 813 minutes in all competitions.|
The German champions and 2013 Champions League winners suffered a momentary lapse in the second period when Gervinho headed past Manuel Neuer, who had earlier denied him with a point-blank save.
It was the first goal Bayern have conceded since 30 August, ending an eight-game run of clean sheets.
They responded by introducing Ribery who ran onto Robben's through ball and lifted a stunning chip over De Sanctis before Shaqiri came off the bench to pounce on a spill by the Roma goalkeeper and complete the rout.
Roma boss Rudi Garcia:
"What did we get wrong? Our strategy; we needed to be tighter and use our players to break out, because our individual qualities lend themselves to that style of play.
"We collapsed tactically and in terms of our aggressiveness. We let a team like Bayern play; they have strong players and we knew that. I was the first to make mistakes; it's not the players' fault. The attitude and strategy in the first half were wrong.
"We were like spectators and I don't like that. At the very least we need to be more compact and aggressive.
"We must accept this defeat because it shows us what steps we must take to get closer to the best teams in the world. We're in second place and can still qualify for the next round, but not if we play like we did tonight.
"Losing to Bayern Munich is normal because they always win, but losing in this way hurts
"The only positive is the draw between CSKA and Manchester City, which means that we're second in the group."
Bayern coach Pep Guardiola:
"This is a fluke, it's not normal to win 7-1.
This is one-off result, it doesn't reflect the true difference between the sides. We still have to play Roma in two weeks and I bet you it won't be the same.
"Last season we had the legs but not the mindset. We needed to decide things a split-second quicker and now we're doing that."
- 26De Sanctis
- 35TorosidisBooked at 56mins
- 3ColeSubstituted forHolebasat 45'minutes
- 15PjanicSubstituted forLjajicat 79'minutes
- 16De Rossi
- 4NainggolanBooked at 56mins
- 7IturbeBooked at 29mins
- 10TottiSubstituted forFlorenziat 45'minutes
- 19GötzeSubstituted forShaqiriat 79'minutes
- 18BernatBooked at 63mins
- 25MüllerSubstituted forFerreira de Souzaat 60'minutes
- 9LewandowskiSubstituted forRibéryat 68'minutes
- 4Costa Santos
- 13Ferreira de Souza
- Jonas Eriksson
- Shots on Target
Second Half ends, Roma 1, FC Bayern München 7.
Attempt blocked. Franck Ribéry (FC Bayern München) left footed shot from the centre of the box is blocked. Assisted by Arjen Robben.
Xherdan Shaqiri (FC Bayern München) wins a free kick in the attacking half.
Foul by Mapou Yanga-Mbiwa (Roma).
Arjen Robben (FC Bayern München) wins a free kick in the attacking half.
Foul by Mapou Yanga-Mbiwa (Roma).
Franck Ribéry (FC Bayern München) hits the left post with a right footed shot from the left side of the box. Assisted by Arjen Robben.
Attempt missed. Arjen Robben (FC Bayern München) right footed shot from a difficult angle on the left is close, but misses to the left.
Attempt missed. Xherdan Shaqiri (FC Bayern München) left footed shot from the left side of the box is too high. Assisted by Arjen Robben with a through ball.
Goal! Roma 1, FC Bayern München 7. Xherdan Shaqiri (FC Bayern München) right footed shot from the right side of the six yard box to the top right corner.
Attempt saved. Rafinha (FC Bayern München) right footed shot from outside the box is saved in the centre of the goal.
Substitution, Roma. Adem Ljajic replaces Miralem Pjanic.
Substitution, FC Bayern München. Xherdan Shaqiri replaces Mario Götze.
Goal! Roma 1, FC Bayern München 6. Franck Ribéry (FC Bayern München) right footed shot from outside the box to the centre of the goal. Assisted by Arjen Robben with a through ball.
Foul by Philipp Lahm (FC Bayern München).
Alessandro Florenzi (Roma) wins a free kick in the defensive half.
Foul by Franck Ribéry (FC Bayern München).
Vasilis Torosidis (Roma) wins a free kick in the defensive half.
Offside, Roma. Miralem Pjanic tries a through ball, but Gervinho is caught offside.