Bayern Munich s Senegalese forward Sadio Mane (L) celebrates with teammates after scoring his team s first goal during the UEFA Champions League 1st round day 5, Group C football match between FC Barcelona and FC Bayern Munich at the Camp Nou stadium in Barcelona on October 26, 2022 (AFP)
Inter Milan thrashed Viktoria Plzen 4-0 earlier on to guarantee progression to the last 16 and send Barca crashing out in the first round for a second successive season.
The Catalans, who drop into the Europa League, had reached the knock-out rounds in the 17 prior editions of the tournament before consecutive early eliminations under coach Xavi Hernandez.
The hosts had hoped to salvage some pride before a large and undeterred crowd of over 84,000 fans, but first-half goals from Sadio Mane and Eric Maxim Choupo-Moting denied them even that, with Benjamin Pavard adding another late on.
A few supporters left at half-time but the majority stayed to the end as their team played their last Champions League game at Camp Nou until at least 2024, with the team set to move to the city's Olympic Stadium next season during renovations.
Barca fans had already mourned their impending, and now confirmed, exit over the past fortnight and despite defeat, the match didn't become the funeral procession it might threatened to.
Xavi selected a similar line-up to the team which convincingly dismantled Athletic Bilbao 4-0 on Sunday, with Pedri operating on the left side but with freedom to float.
A cut above
Bayern, already through, were without injured goalkeeper Manuel Neuer, defender Lucas Hernandez and winger Leroy Sane, but still put out a strong line-up.
Despite strong home support, hoping their team could end a run of five consecutive defeats by the Bavarians for pride as much as anything else, the visitors clinically took the lead after 10 minutes.
Serge Gnabry played a fine through ball for Sadio Mane to race on to, leaving Hector Bellerin chasing hopelessly behind, and the Senegalese forward lofted over Marc-Andre ter Stegen.
Barcelona tried to strike back, with Ousmane Dembele their main outlet on the right, but after a brilliant run past several defenders he could not find Pedri in the area.
Just like the Catalans' recent Clasico defeat by Real Madrid, at times they had the upper hand, but their smarter opponents knew the right time to pounce.
Bayern sliced Barcelona open like a hot knife through butter again in the 31st minute, with former Stoke City and PSG striker Eric Maxim Choupo-Moting finishing consummately after another Gnabry pass. The Cameroon international now has five goals in his last four games.
Julian Nagelsmann's team could have added a third before half-time but the otherwise ragged Hector Bellerin blocked on the line and Ter Stegen denied Jamal Musiala from close range.
Moments later Barcelona won a penalty when Robert Lewandowski was felled by Matthijs de Ligt, but after watching the incident again, referee Anthony Taylor cancelled it, provoking vitriol from Camp Nou.
Home supporters, and their coach Xavi, feel hard done by in Europe this season, after decisions did not go their way in Milan in a 1-0 defeat by Inter which hamstrung their chances of progression, and this felt like salt in the wound -- although De Ligt took the ball.
Gnabry had a goal ruled out for offside in the second half just when it seemed Bayern had again masterfully absorbed Barcelona's pressure and sucker-punched them at the other end.
Bayern rounded off their victory when Pavard finished from close range after a corner was fired back his way.
Former Bayern striker Lewandowski, who swapped the Allianz Arena for Camp Nou in the summer, left frustrated again, unable to net against his old side, one of the favourites for Champions League glory.
Barcelona will be among the favourites in Europe too, albeit for a different trophy.
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