The DFB are to investigate how Eintracht Frankfurt were not given a penalty in their 1-0 defeat to Augsburg on Sunda
Hannover piled the pressure on their former coach Mirko Slomka with a 2-0 victory over his Hamburg.
Augsburg picked up their first win of the season by beating Eintracht Frankfurt 1-0.
Lucas Piazon remains keen to make his mark at Chelsea, but is open to a permanent move to Eintracht Frankfurt.
Bayern Munich were held to a 1-1 draw by Schalke, while Bayer Leverkusen ran out 4-2 winners against Hertha Berlin.
Wolfsburg are still waiting for their first win as substitute Vaclav Kadlec earned Eintracht Frankfurt a 2-2 draw.