Lahm said that scoring before Plzen could build any momentum from missed chances was vital and that after that point Bayern pressed on for a comfortable win.
"It's always fun when you're winning," UEFA.com quotes Lahm as saying. "We went ahead at the right time and pressed on from there; we made it look pretty easy in the end.
"We didn't score in the first 20 minutes but we created a lot of very good opportunities and there was plenty to build on from the performance."
Bayern have nine points from their first three games and top Group D.