Bruno Labbadia became the second German league coach to be sacked this season after Hamburg announced Sunday they fired him in the wake of his team's fourth straight defeat.
Labbadia returned for his second stint with Hamburg in April 2015, but was shown the door for the second time after his team's 1-0 loss at home to defending Bundesliga champions Bayern Munich.
His team had held Carlo Ancelotti's Bavarian giants until Joshua Kimmich's 88th-minute goal decided Saturday's match.
With one point in five league games, Saturday's defeat left them third from bottom.
Hamburg's board has lost patience after the latest setback following league defeats to Bayer Leverkusen, plus newly promoted teams Freiburg and RB Leipzig.
"This step is necessary in view of recent results," said Managing Director Dietmar Beiersdorfer.
"I am convinced that we have to now make a change to the coaching position in order to turn things round after a disappointing start to the season."
Labbadia was informed of his dismissal by telephone after 529 days in charge and used the club's Facebook page to thank staff and fans.
"It was a crazy intense time with many experiences that I will always remember," wrote Labbadia.
"I hope that the team keep up the brave performance from the game against Bayern to get back on the path to success."
The favorite to take over is ex-Hoffenheim coach Markus Gisdol, 47.
With only five league games played so far this season, Labbadia, 50, is the second Bundesliga coach sacked in the space of a week after Werder Bremen fired Viktor Skripnik. This is the second time Hamburg have sacked Labbadia, who spent less than a year at the club in the 2009-10 season.
Hamburg face tough forthcoming German league games when travel to Hertha Berlin on Saturday and then play Borussia Moenchengladbach on October 15.