A late Franco Di Santo penalty bagged all three points for Werder Bremen against Hamburg.
Hamburg have appointed Bruno Labbadia as coach with immediate effect in a bid to preserve Bundesliga status.
Relegation-threatened Hamburg confirmed Sunday that their players came to half-time blows during their latest defeat.
Wolfsburg returned to within 10 points of Bundesliga leaders Bayern Munich with a 2-0 win in Hamburg.
Bayer Leverkusen made it a debut to forget for new Hamburg coach Peter Knabel, thrashing the northern Germany side 4-0.
Robert Lewandowski was the difference in the German Klassiker, while there were wins for Monchengladbach and Leverkusen
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