كتب : Amro Hassan
Summer signing Ivica Olic of Croatia opened the score line for Bayern in the 25th minute before Obasi drew level for Hoffenheim on 41 minutes.
The Bavarians kicked off their Bundesliga season without defender Martin Demichelis, winger Franck Rivery and strikers Luca Toni and Miroslav Klose, who are all injured.
Olic and Mario Gomez were given their debuts in the Bayern attack.
The game also witnessed the return of Bosnian striker Vedad Ibisevic, who was injured for the second half of last season after scoring 18 goals in the first term.
Olic's goal came against the run of play thanks to a cross from fellow Croatian Danjiel Pranjic.
Obasi beat Michael Rensing in the Bayern goal with a shot after a lay off from Ibisevic.