Hamburg increased the pressure on under-fire Hoffenheim coach Markus Gisdol as Pierre-Michel Lasogga's late goal gave them a 1-0 away win at the Rhein-Neckar Arena.
With Hoffenheim having taken only six points from nine games coming into the clash, reports in the German media had suggested Gisdol would be sacked if Hoffenheim suffered defeat in Friday's contest.
A first half of few chances saw the best opportunity fall to Hamburg, who were denied by a fine double save from Hoffenheim goalkeeper Oliver Baumann, who kept out efforts from Nicolai Muller and Lasogga in quick succession in the 23rd minute.
Hoffenheim's task was made harder in the 68th minute when defender Ermin Bicackic was sent off after receiving a second yellow card for a foul on Sven Schipplock.
And Hamburg finally capitalised on their numerical advantage two minutes from time as Schipplock squared the ball for Lasogga to tap home at the far post to finish off a well-worked move and secure all three points.
Hamburg are now ninth in the table on 14 points, while Hoffenheim remain second bottom.
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