The Sack of Niko Kovac might not have had any effect on the players as Bayern schools rivals Borrusia Dortmund 4-0 in Saturday’s Bundesliga fixture.
Lewandowski, who hit two goals, has scored in all 15 of Bayern’s European and Bundesliga games this season, with a tally of 22 across both competitions.
England forward Jadon Sancho was substituted after 36 minutes for Dortmund with an injury.
Bayern move to third in the Bundesliga, with Dortmund in fifth.
Bayern, who are chasing their seventh consecutive Bundesliga title, are now level on points with second-placed RB Leipzig and a point behind leaders Borussia Monchengladbach, who host Werder Bremen on Sunday (12:30 GMT).
And Lewandowski was again responsible for carrying their main threat in front of goal.
The Poland forward opened the scoring against his former employers with a brilliant diving header from Benjamin Pavard’s cross before sweeping in his second of the night from Thomas Muller’s pass.
Serge Gnabry’s tap-in and a Mats Hummels own-goal, either side of Lewandowski’s contributions, rounded off the scoring for the hosts on a miserable evening for Dortmund at the Allianz Arena, with the visitors having now shipped 15 goals across their last three visits.
Hansi Flick took charge of Bayern for a second consecutive game after former boss Niko Kovac left the club last Sunday
There was little by the way of encouragement for Dortmund fans throughout the evening as their team failed to register a shot on target.
They were not helped though by Sancho struggling to make an impact as he clearly nursed an injury, before being replaced by Raphaël Guerreiro.
The 19-year-old had been a doubt for the game after suffering an injury during Dortmund’s 3-2 Champions League win over Inter Milan on Tuesday.
And his withdrawal may cast a doubt over his availability for England’s Euro 2020 qualifiers against Montenegro on 14 November and Kosovo on 17 November.