Bayern, their worst start to a season in 43 years firmly behind them, offered a thrilling taste of what they are capable of as they made it two successive wins either side of the international break.
Coach Louis van Gaal can even be confident he has Franck Ribery fully on side, after the French playmaker rushed over to hug him after scoring in the second half of the away game.
"Franck showed today he loves this coach," Van Gaal said of a player who earlier in the season was widely quoted as saying there was little "feeling" between the two of them.
"We started badly today," Van Gaal added after watching his team, missing the injured Miroslav Klose, fall behind in the 10th minute.
"I explained to the players that we did not do anything right in the beginning," the coach told reporters.
Defensively, Edson Braafheid again looked the weak link in the absence of the injured Martin Demichelis.
But if fans thought it would be a repeat of their previous uninspiring Bundesliga performances they were wrong.
The Bundesliga's most expensive signing, Mario Gomez, pulled one back nine minutes before the break with a close range header before Ribery took over in the second half.
The Frenchman, still lacking match fitness following a string of injuries, came off the bench and almost immediately helped set up Bastian Schweinsteiger's goal.
He then put the game beyond Dortmund with a beautifully curled free kick before rushing off to put his arms around the coach.
Teenager Thomas Mueller grabbed two late goals end to complete the demolition.
"We made a demonstration of our individual skills in the second half and that made the difference," Van Gaal said. "I am very happy for these beautiful goals after a tough week."
