MISSED the match? Catch Up via beIN SPORTS CONNECT | 2-week free trial

Julian Nagelsmann's side was knocked out of the Champions League by Villarreal in midweek, leaving the Bundesliga as the only trophy they can claim this season.

Borussia Dortmund reduced the gap to six points on Sunday (AEST) with a thumping 6-1 win over Wolfsburg on Saturday.

However, Bayern ensured it will go into Der Klassiker against Dortmund with a comfortable buffer, goals from Robert Lewandowski and Serge Gnabry, both of which were originally disallowed for offside, and some late gloss courtesy of Jamal Musiala keeping them on course for a 10th consecutive Bundesliga crown.

Arminia started brightly and the impressive Patrick Wimmer fired into the side-netting after cutting in from the right.

But Bayern soon took control of the contest, with only an astonishing save denying Robert Lewandowski as Stefan Ortega Moreno pushed his close-range header onto the post and then off the underside of the crossbar.

Lewandowski then looked to have been thwarted by the offside flag after he met Alphonso Davies' cross and saw his effort deflected in by a defender, however, the VAR overturned the decision to give Bayern lead.

Ortega's battle with the Poland striker continued as he repelled another effort after more good work from Davies as Bayern piled further pressure on the Arminia goal.

Arminia then saw two more offside decisions go against them as a well-taken Masaya Okugawa goal was chalked off in a decision confirmed by VAR before Gnabry found the bottom-left corner with a first-time strike that was awarded after originally being disallowed by the linesman's flag.

Bayern took the sting out of a low-key second half with little difficulty and Musiala tapped in at the near post six minutes from time to put the result beyond any doubt.