Having vowed to reduce his level of squad rotation prior to Saturday's encounter at Allianz Arena, under-pressure Bayern coach Niko Kovac named an unchanged team and his faith was repaid by a dominant display.
Lewandowski's ninth-minute header opened the floodgates, with the 30-year-old doubling his tally after Franck Ribery and Leon Goretzka had hit the woodwork.
Ribery's first goal of the season added further gloss before the hour, but Bayern – now up to second in the table – remain nine points behind leaders Borussia Dortmund, who beat Schalke 2-1 in the Revierderby.
Nurnberg's resolve was short-lived – Lewandowski capitalising on hesitant goalkeeping from Fabian Bredlow to head in from Joshua Kimmich's inswinging corner.
Bredlow palmed Ribery's effort onto the frame of the goal before Lewandowski sliced over from close-range, but the forward did not miss in the 27th minute, tapping home after Goretzka's wicked long-range effort had been magnificently tipped on to the crossbar by Nurnberg's goalkeeper.
Bredlow came to Nurnberg's rescue after the restart, which was slightly delayed due to sections of Bayern's support launching toilet roll onto the pitch, getting down to tip Kimmich's strike wide after Lewandowski had turned provider with a deft flick.
Yet Bredlow was to blame for Bayern's third when he conceded possession from a goal kick. Although he kept out Serge Gnabry's initial effort, Ribery hammered in the rebound.
Kimmich almost rounded off a superb individual display in style late on, but his dipping strike clipped the crossbar as Bayern cruised to a routine win.
Consistency the key for Kovac
Bayern's torrid start to the campaign by their high standards has not been helped by Kovac's tinkering, but the former Eintracht Frankfurt coach seems to have settled on a preferred starting XI that has now claimed back-to-back wins, and a seventh straight victory over Nurnberg.
Lewandowski leads the way
Lewandowski has now netted 19 goals from 20 appearances in all competitions this season, more than any other player across Europe's five major leagues. With the striker in this kind of form, Bayern will still hold out hope of catching Dortmund.
