Bayern Munich crushed Stuttgart to move ominously to the top of the Bundesliga on a day when the league's most expensive arrival made his debut.
Javi Martinez only played the last 13 minutes, by which time Bayern had already put the three points in the bank with goals from Thomas Muller (two), Toni Kroos, Bastian Schweinsteiger, Luiz Gustavo and Mario Mandzukic.
Vedad Ibisevic was shown a red card on a torrid afternoon for Stuttgart, who slumped to the bottom of the table after their second defeat of the season.
Martinez had to wait before making his Bayern debut as the Bundesliga's record signing was left on the bench by Bayern coach Jupp Heynckes.
He probably would not have been able to do anything about the goal which put Stuttgart in front in the 25th minute, though, as Artur Boka's free-kick was met on the volley by Harnik, who beat Manuel Neuer.
Two goals in as many minutes turned the game back in Bayern's favour just after half an hour's play.
Muller brought them level when he beat Sven Ulreich at the second attempt after his initial volley was saved by the Stuttgart custodian.
Before Stuttgart could regroup, Kroos had the ball in the back of the net once again with Luiz Gustavo setting him up to rifle a powerful shot into the roof of the net from just outside the penalty area.
Luiz Gustavo put Bayern in the driving seat just two minutes before half-time when he bettered Kroos with a shot from 30 yards into the bottom corner.
Worse was to come for Stuttgart in the second half as they conceded three goals in just four minutes.
Mandzukic scored Bayern's fourth in the 47th minute, pouncing on the loose ball after Ulreich pushed Muller's shot away.
Muller scored his second of the game two minutes later with the roles reversed this time as Mandzukic's shot was parried by the Stuttgart custodian to the awaiting Germany international.
Schweinsteiger concluded four productive minutes for Bayern with his first goal of the season, heading Muller's cross past an increasingly bewildered Ulreich.
A frustrating afternoon took its toll on Ibisevic, who was shown a straight red card for attacking Jerome Boateng with his head after a strong tackle between the pair saw Boateng penalised with a yellow card.
Martinez made his entrance in the 77th minute to pick up his first experience of life at the Allianz Arena, but the job had already been done as far as Bayern were concerned and the most the Spaniard learnt was how to celebrate in front of the fans at the final whistle.