Lewandowski opened the scoring once visiting goalkeeper Markus Schubert fumbled Thomas Muller’s cross.
Muller and Lewandowski each had goals disallowed before the German doubled Bayern’s lead late within the half.
Second-half strikes from Leon Goretzka, Thiago Alcantara and serge Gnabry completed the scoring.
Lewandowski is that the first player to net twenty one goals within the opening nineteen games of a Bundesliga season since Gerd Muller in 1972-73.
The Poland international capitalised on Schubert’s early error to grant Bayern the lead, slotting into AN empty net from close range.
Welsh forward Rabbi Matondo went near to AN equaliser once his shot from the edge of the box was deflected on to the crossbar by Jerome Boateng, however Bayern continuing to put encirclement to the visitors’ goal.
Muller’s instinctive end was dominated out for offside , before var disallowed Lewandowski’s powerful effort once full-back Benjamin Pavard had strayed into AN offside position.
Germany striker Muller wasn’t to be denied although, converting Goretzka’s knock-down on the stroke of half-time for his one hundredth Bayern goal altogether competitions at Allianz Arena.
Ex-Schalke midfielder Goretzka rubbed salt into his former club’s wounds with an impressive scissor-kick 5 minutes into the last half, before Lewandowski teed up Thiago for an easy end eight minutes later.
Second-half substitute Gnabry capped a comprehensive finish within the final minute of normal time, beating Schubert from the edge of the area once cutting in from the left flank.
Earlier on weekday, leaders Rb Leipzig slipped to a surprise 2-0 defeat at Eintracht frankfurt.
After dominating the primary half, Julian Nagelsmann’s side fell behind through Almamy Toure’s first Bundesliga goal before Filip Kostic completed the scoring in second-half stoppage time.
RB Leipzig host Borussia Monchengladbach next weekday before travelling to Bayern in their next away league match.
Monchengladbach are currently simply 2 points behind the league leaders after beating troubled Mainz 3-1 at home.
Robin Quaison gave Mainz a shock lead, however AN Alassane Plea double and a further strike from Florian Neuhaus sealed a comfortable finish for the hosts.
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