FC Porto manager Julen Lopetegui was forced into two changes after full-backs Danilo and Alex Sandro were suspended with Diego Reyes joining Dutch international Bruno Martins Indi in the starting line-up.
It was a devastating night for Portugal’s only remaining European combatant as the visitors were blown away with Bayern scoring five times before the break. Bayern’s Lewandowski hit the woodwork early on and former Olhanense goalkeeper Fabiano had a night he will want to forget.
Thiago headed home at the near post after fifteen minutes and seven minutes later Jerome Boateng added a second. All square on aggregate but minutes later Lewandowski put Bayern in front in the tie, as he headed low past Fabiano after great work from Philipp Lahm and Muller to keep the ball in play down the right channel.
This was the first time that Bayern Munich had overturned a two-goal deficit in the Champions League. Porto were completely outclassed as Thomas Muller and Lewandowski made it five inside forty minutes.
The FC Porto defence were chasing shadows but Jackson Martinez gave Porto a ray of hope when he reduced the arrears on 73 minutes, the first goal that the German Bundesliga champions had conceded at home in the competition this season.
The Colombian international then missed a glorious chance to set up what would have been a grandstand finish, before their hopes of an unlikely comeback were dashed when Ivan Marcano picked up a second yellow card from English referee Mark Atkinson.
The night went from bad to worse for Porto as manager Lopetegui was sent to the stands for his protest, before Alonso sealed Bayern’s passage to the last four with a delightful curling free-kick. Porto must now pick themselves up for the all-important clássico game against Benfica this Saturday in Lisbon at the Stadium of Light.
Given that both teams will probably win their remaining fixtures, FC Porto must win by two clear goals in front of a partisan sell-out crowd if they are to have any realistic chance of prising the Primeira Liga title away from the Eagles.