Trailing 3-1 from the quarter-final first leg, Pep Guardiola's side produced a devastating first-half display, scoring five times in the opening 40 minutes to leave the visitors shell-shocked.
Defensive errors had cost Bayern dear in the opening encounter, but it was their supreme attacking quality that came to the fore at the Allianz Arena.
Club doctor Hans-Wilhelm Muller-Wohlfahrt resigned in the wake of last week's reverse, claiming his medical team had been blamed for the defeat, but even without the absent trio of Bastian Schweinsteiger,Arjen Robben and Franck Ribery, Guardiola's team simply had too much for the 2004 winners.
Thiago Alcantara - who netted Bayern's away goal at the Estadio do Dragao - opened the scoring inside quarter of an hour and it was 3-0 before the 30th minute thanks to further goals from Jerome Boateng and Robert Lewandowski.
Thomas Muller's deflected effort made it four, before Lewandowski doubled his tally with a clinical finish as Porto failed to live with Bayern's movement and incisiveness.
With the job done for the Bundesliga champions, the second half proved a low-key affair, Jackson Martinez's goal 17 minutes from time proving nothing more than consolation, especially as there was still time for Xabi Alonso to curl home a late free-kick following a tackle that saw Marcano sent off for his second booking.
Bayern suffered a nightmare first 10 minutes in the opening leg when they found themselves 2-0 down, but there were no such mishaps here and it proved a sign of things to come when Muller's shot was saved by Fabiano and Lewandowski sent the rebound against the upright.
Guardiola's men did not have to wait long to break the deadlock, however, as Thiago headed in Juan Bernat's left-wing cross in the 14th minute.
And eight minutes later, Bayern doubled their advantage.
Holger Badstuber - selected ahead of Dante in Bayern's only change from the first leg - nodded a cross towards Boateng, who headed beyond Fabiano into the bottom right-hand corner.
Porto's night went from bad to worse in the 27th minute as Muller flicked on Philipp Lahm's driven cross and Lewandowski was left unmarked to plant his header into the net from eight yards.
Muller then got in on the act for Bayern as his speculative shot from distance took a wicked deflection off Bruno Martins Indi, wrongfooted Fabiano and trickled beyond the goalkeeper's feeble attempt and into the net.
With five minutes still to go until the break, Muller teed up Lewandowski, who made space for himself inside the area and shot low into the left-hand corner as Bayern ran riot.
Badstuber was perhaps fortunate only to receive a yellow card for a dangerous lunge on Ricardo Quaresma before Martinez's close-range header from Hector Herrera's cross left Porto needing two more.
Martinez went close with a low shot soon afterwards, but Porto's faint hopes were extinguished when Marcano was dismissed for a second bookable offence and Alonso curled the resulting free-kick into the left-hand corner.
The result capped a fine way for Bayern to celebrate Guardiola's 100th match in charge in style, this marking his 77th win in that time, and few can have come more convincingly than this.
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