The reigning champion tasted its first defeat of Julian Nagelsmann's tenure at home to Eintracht Frankfurt prior to the international break, but it responded in dominant style at BayArena.
After going back-to-back league games without scoring for the first time in two years, Robert Lewandowski flicked Bayern into the lead inside three minutes in Sunday's match.
Lewandowski scored a second on the half-hour mark and Thomas Muller was next on the scoresheet four minutes later.
Serge Gnabry added a quickfire brace of his own, the Germany international dinking in Bayern's fourth of the contest before slotting in number five two minutes later.
Only twice before in Bundesliga history has an away side scored five goals in a quicker time from kick-off – Borussia Dortmund against Schalke (23 minutes) and Karlsruhe versus Frankfurt (30 minutes), both in 1964.
There have been 10 occasions when teams have scored five or more goals in the first half of a Bundesliga game this century, with Bayern responsible for six of those 45-minute thrashings, including when they put five past Dortmund before the break in March 2018 on the way to a 6-0 win.
Leverkusen is no stranger to one-sided first halves, meanwhile, as it is the only team to have scored six goals in the opening 45 minutes of a match in the division since the turn of the millennium, doing so in its 6-1 win over Eintracht Frankfurt in 2018-2019.