Hamburg survived for almost an hour with 10 men to secure a Bundesliga victory over northern German rivals Werder Bremen.
Joris Mathijsen gave Hamburg the lead after nine minutes, but Bruno Labbadia's men had Jerome Boateng sent off for a professional foul after 32 minutes. The hosts responded from the setback four minutes later by doubling the lead through Marcell Jansen and Naldo's late strike proved mere consolation for Bremen, who also struck the crossbar three times.
"This is a fantastic result for us," Hamburg coach Bruno Labbadia told reporters. "This was the cherry on top of a first half to a season which had everything. Our best start ever and extremely bad luck with injuries. My team took it all and we are now in touch with the top spots. We can only be satisfied."
It was Bremen's second straight Bundesliga loss following a 23-game unbeaten streak and the showdown in Hamburg was the first game since these two teams faced off four times within 19 days in the semi-finals of the German Cup and UEFA Cup and the Bundesliga late last season.
Elsewhere, Cologne ended a run of four games without a goal with a 3-0 success over second-bottom Nurnberg.
Cologne came into the game having scored just twice in their last 10 league games, but goals from Pedro Geromel (34) and Milivoje Novakovic (70,77) sunk the visitors, who had Juri Judt sent off six minutes from time.