European champions Bayern Munich laboured to a 1-0 win at Eintracht Frankfurt while both Hamburg and UEFA Champions League side Schalke 04 suffered heavy defeats in the Bundesliga on Saturday.
Croatia striker Mario Mandzukic gave Bayern the three points at Eintracht, who were humbled 6-1 at Hertha Berlin the previous weekend, when he volleyed home a cross from Germany's Thomas Muller on 13 minutes. But it was a rare highlight in a below-par performance as Bayern failed to dominate Eintracht, whose captain Alex Maier had a clear penalty appeal turned down in the dying stages.
Before the match, Bayern's director of sport Matthias Sammer told German daily Bild that the defending champions must raise their standards. "At the moment, others (in the league) may feel that they have a hope against us, but we have to make sure they get the feeling again that they have no chance," he said, but his words failed to fire the Bavarians in Frankfurt.
Bayern coach Pep Guardiola, taking charge of only his second Bundesliga match, started with Dutch winger Arjen Robben, Germany star Mario Gotze and new-signing Thiago Alcantara all on the bench, while Spain's Javi Martinez failed to even make the matchday squad.
Brazil midfielder Luiz Gustavo, who signed for Wolfsburg last week from Bayern after rejecting offers from Arsenal and Barcelona, made his Die Wolfe debut in their 4-0 win at home to Champions League side Schalke 04.
Die Königsblauen lost Dutch international striker Klaas-Jan Huntelaar at the break with a knee injury and the hosts took full advantage with three goals in 12 second-half minutes by defender Knoche, Portugal midfielder Vieirinha and Brazil defender Naldo. Wolfsburg striker Stefan Kutschke then hit the fourth just five minutes after coming off the bench.
Having drawn 3-3 at Hamburg last Sunday, Schalke need to find some form ahead of their Champions League play-off first-leg at home to Greece's PAOK on August 28.
Hamburg were humbled 5-1 at home to Hoffenheim as Brazilian striker Roberto Firmino ran riot, scoring twice and setting up the other three. Firmino's forward partner, Frenchman Anthony Modeste, a new signing from French league outfit Bastia, had plenty to boast about with two well-taken second-half goals.
Mainz enjoyed a 2-1 win at Freiburg while Champions League side Bayer Leverkusen picked up their second win of the season with a 1-0 victory at VfB Stuttgart thanks to an own goal by the hosts' defender Daniel Schwaab. Bremen also enjoyed another win on the second weekend of the Bundesliga season with a 1-0 victory at home to Bavaria's Augsburg.
Borussia Monchengladbach bounced back from defeat on the opening day of the Bundesliga season by picking up their first three points with victory over Hannover.
Max Kruse, Christoph Kramer and Filip Daems all scored for Lucien Favre's men as Hannover were given short shrift at the Borussia Park Stadion.