Hamburg have appointed Markus Gisdol after coach Bruno Labbadia was sacked for a second time following a poor start to the season.
Pierre-Emerick Aubameyang struck twice as Borussia Dortmund beat Wolfsburg 5-1 to go top of the Bundesliga, while Hamburg lost to Freiburg.
Bayern Munich opened up a two-point advantage at the top of the Bundesliga after a 3-1 win over Ingolstadt on Saturday.
Leipzig picked up a first Bundesliga win in their maiden home fixture with a 1-0 win over Borussia Dortmund, while Leverkusen beat Hamburg.
Borussia Dortmund respond to Bayern Munich with opening day win thanks to Pierre-Emerick Aubameyang's double.
Hamburg supporters have started a petition to sign Wigan Athletic and Northern Ireland forward Will Grigg.