Bayern struggled in the first game after the international break and was the only side across all matches being played not to register a shot on target in the first half. Mainz, in contrast, had two inside the first 15 minutes.
The visitors scored in the 44th minute, when a mistake from Jerome Boateng allowed Shawn Parker through to round Manuel Neuer.
”We always have problems in the first half at home. But I’m sure we’ll improve that quickly,” Bayern coach Pep Guardiola said. ”I can’t tell people that they can only come here for the second half.”
There were whistles from the home fans at the interval, when Guardiola reacted by sending on Goetze for Rafinha, a defender.
Goetze duly set up Arjen Robben to equalize in the 50th, combined with Robben to set up Thomas Mueller two minutes later, and then crossed for Mario Mandzukic to score from close range in the 69th.
Mueller completed the scoring with a penalty in the 82nd, after Bastian Schweinsteiger was pushed down by Nikolce Noveski. Robben was visibly annoyed when he was told he wouldn’t be taking the spot kick. Goetze appeared to calm the Netherlands winger before Mueller stepped up to score his second.
”We’re here with a Volkswagen Beetle built in ’70 against a Formula One car,” Mainz coach Thomas Tuchel said. ”So it’s normal that you’re overtaken in the end.”
It was Bayern’s 34th successive Bundesliga game without defeat, edging it closer to Hamburger SV‘s record 36-match run without a loss.
Franck Ribery missed the game with an ankle injury. The Frenchman could have set a new Bundesliga record of playing 39 games without defeat. For now he shares Holger Hieronymus’ record set while playing for Hamburg from September 1981 to January 1983.
Ribery is expected to be fit for Viktoria Plzen’s Champions League visit on Wednesday, but Dante is ruled out. The Brazilian defender needed stitches on his left foot after going off injured in the first half, and will be sidelined for up to two weeks.
Marco Reus’ fourth-minute penalty was enough for injury-hit Dortmund to stay one point behind Bayern in the standings, after Hannover defender Hiroki Sakai impeded stand-in left back Erik Durm in the area.
”I’m totally satisfied,” said Dortmund coach Juergen Klopp, whose side next faces Arsenal away on Tuesday in the Champions League. ”We knew it would be really difficult today. For me it was decisive that the lads could deal with the situation.”
Schalke, which hosts Chelsea in the Champions League on Tuesday, needed goals from Max Meyer and Leon Goretzka to equalize after Orhan Ademi and Karim Bellarabi had twice given Braunschweig the lead.
”When you lose a game in such a manner, it’s a blow,” Braunschweig coach Torsten Lieberknecht said.
Nuremberg drew 1-1 at Eintracht Frankfurt thanks to an 86th-minute equalizer from Josip Drmic in the visitors’ first game without dismissed coach Michael Wiesinger. Vaclav Kadlec scored in the 50th for Frankfurt.
Werder Bremen drew 0-0 with visiting Freiburg in the Bundesliga’s first scoreless draw – after nine rounds of games.