It was a somewhat subdued atmosphere inside a full-capacity Camp Nou, with boos ringing out as the UCL anthem rang out.
Bayern knew that a draw would seal top spot, but were set to show no mercy as Sadio Mané (30) found it all too easy to break the deadlock inside 10 minutes.
The Senegalese international made it double figures in a Bayern shirt as he latched onto a defence-splitting pass from Serge Gnabry (27), outrunning Héctor Bellerín (27) before chipping coolly beyond Marc-André ter Stegen’s reach.
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The Bavarians could smell blood against the wounded Barça juggernaut and added insult to injury prior to HT, again looking so smooth in counter-attacking transition.
Gnabry was yet again the provider, feeding Eric Maxim Choupo-Moting’s perfectly timed run before he thrashed his effort through the legs of a helpless Ter Stegen.
English referee Anthony Taylor even had time prior to HT to get in on the humiliation act, being assisted by VAR in overturning a penalty he had given moments earlier for a tackle on Robert Lewandowski (34).
It was an early exit for a number of the embarrassed Catalan crowd at HT, who would’ve been counting their blessings as Gnabry curled in a third moments later.
That was until 19-year-old left back Alejandro Balde (19) was fortunately reprieved when replays showed he had played Gnabry marginally offside as Joshua Kimmich (27) floated the ball over.
Barcelona offered very little in way of response, failing to muster a single shot on target in a toothless performance before Benjamin Pavard (26) capped off the scoring moments from time, tapping home a third.
Bayern extended their record unbeaten 33-game run in the UCL group stages and have now won their last five games against Barcelona, scoring 18 and conceding just two.
For Barça, they now join fellow heavyweights Juventus and Atlético Madrid in Europe's second-string competition.
Flashscore Player of the Match: Serge Gnabry (Bayern Munich)
