The German champions inflicted a heaviest ever European defeat on Barca with a mesmerising display in Lisbon.
They were 4-1 up after 31 minutes and then hit four more in the final half with Muller(2), Ivan Perisic, Serge Gnabry, Josh Kimmich, Robert Lewandowski and Phillipe Coutinho (2) all scoring as Hansi Flick’s side ran riot.
Boss Quique Setien will surely pay the price for this embarrassment, coming after a limp end to their league campaign, and questions over the future of this side will be asked.
They had levelled at 1-1 through David Alaba’s own goal and then Luis Suarez got one back just before the hour, but there was to be no comeback.
Barcelona president Josep Maria Bartomeu has said decisions have already been made.
“It has been a very, very tough night. I am sorry for the Barça fans and members, for the players. For everyone. We were not the club that we represent, am so sorry,” he said on the club’s website.
“Here are some decisions that we had already made, and others that we will make over the next few days. Announcements will be made from next week, we need to make decisions after things have calmed down.
“Today is a day for reflection. Tomorrow we will try to raise our fans’ spirits following such a heavy defeat.
“It was a devastating result. I congratulate Bayern, they played a great game and deserved to go to the semi-finals. We were not up to the occasion, and we can only apologise to the members and fans.”
Defender Gerard Pique said: “I’m in pain. We all are. We can’t compete like that.
“It’s very, very tough to take. We must change the dynamic we are on. Is it an end of an era? I’m not sure but I know that we must accept that we have hit the bottom.”