Mario Götze also struck twice, with further efforts from Xabi Alonso and Thomas Müller, as the hosts put on a ruthless display to leave Bremen still without a win in 2014/15.
Bayern coach Pep Guardiola left Robert Lewandowski, Juan Bernat and Franck Ribery on the bench, and brought Danish youngster Pierre-Emile Hojbjerg into midfield as the Bavarians began with a side that had never started together before. It made little difference to the opening exchanges though, as the hosts greedily kept hold of possession and pegged Bremen back into their own half.
However, the visitors were playing with three holding midfielders, Felix Kroos, Cedric Makiadi and Zlatko Junuzovic, and as such there was very little space for Bayern to exploit, with a long-range Götze effort the closest they came to scoring early on. Bayern finally broke through with 20 minutes gone though, as David Alaba won the ball back on the left wing before crossing for Müller, who nudged the ball back with his thigh for Lahm to drive into the net.
Alonso off the mark
Bayern wasted little time in extending their lead, and did so in fine style too. After Hojbjerg won a free-kick on the edge of the penalty area, Alonso swept the ball under the wall and past static Bremen keeper Raphael Wolf to net his maiden goal for the club. There was worse to come for the guests, who completely capitulated just before half time.
After Sebastian Prödl fouled Müller just inside the area, the Germany international stepped up to coolly side-foot the ensuing penalty past a wrong-footed Wolf, before Götze added a fourth, freeing himself with a sensational turn to curl a delightful shot into the top corner. The hosts should have added a fifth shortly after the restart following superb interplay between Götze and Arjen Robben, but the latter blazed over the bar with his right foot from ten yards out.
With an eye on Bayern’s UEFA Champions League match away to AS Roma on Tuesday, Guardiola replaced Alonso and Robben with Xherdan Shaqiri and Ribery, who tasted Bundesliga action for the first time since Matchday 3 after recovering from injury. The defending champions continued to control proceedings, but no longer had the same drive going forward with the points all but secured.
Lahm did manage to notch his second of the afternoon - his first ever Bundesliga brace - in the closing stages to crown a superb performance, flicking a back-heeled pass to Shaqiri before collecting the return ball and rolling it under Wolf. Götze fired in his second late on to ensure there will be no change at either end of the table this week, as Bayern moved on to 20 points to leave Bremen rooted at the bottom with just four.
Line-ups and statistics
Jonathan Stockitt reporting from the Allianz Arena