Substitute Mario Goetze led Bundesliga leaders Bayern Munich on a second-half four-goal rampage after midtable Mainz 05 had the temerity to take a halftime lead at the Allianz Arena in Munich, on Saturday.
Goetze set up the first three Bayern goals in the 4-1 win after Shawn Parker had pounced on a Jerome Boateng error to put the visitors ahead in the 44th minute, briefly threatening to end Bayern's 33-match unbeaten league run.
An early penalty from Marco Reus agave Borussia Dortmund a 1-0 win over Hanover 96 while Roman Neustaedter scored in stoppage time as Schalke 04 twice came from behind to win 3-2 at Eintracht Braunschweig.
Josip Drmic also scored late in the game to give Nuremberg a 1-1 draw at Eintracht Frankfurt where Vaclav Kadlec opened the scoring. Nuremberg remained without a league win this season as did Freiburg, who held Werder Bremen 0-0.
Bayern, with 23 points from nine games, quickly overhauled Leverkusen (22 points), who had briefly gone top on Friday with a 2-1 win at Hoffenheim, courtesy of a Stefan Kiessling header which entered the net through a hole in the side rather than the goal.
Kiessling apologised on Saturday while the German football federation (DFB) said it would study Hoffenheim's appeal for a replay, but only after consultations with soccer's governing body FIFA.
Dortmund also have 22 points after doing the absolute minimum against Hanover, who had a stoppage time penalty appeal turned down.
Bayern's only defeat in 13 matches since Pep Guardiola took over at the start of the season was in the season-opening Supercup match against Borussia Dortmund.
After a dreary opening half, Boateng misjudged Julian Baumgartlinger's long pass forward allowing Parker to nip in and give Mainz a shock lead.
Bayern were behind for only six minutes before halftime substitute Goetze laid the ball off perfectly for Dutchman Arjen Robben to spring the offside trap and fire the equaliser.
Two minutes later Goetze and Robben again combined to set up Thomas Mueller, and Bayern were ahead.
Goetze also provided the pass for Mario Manzukic to add the third in the 69th minute before Mueller completed the rout with a penalty eight minutes from time.
Image: Mario Goetze
Photograph: Laurence Griffiths/Getty Images