Hamburg were blown away by former player Sidney Sam.
Die Werkself took the lead on the half-hour somewhat against the run of play. Tranquillo Barnetta's cross was headed on from the penalty spot by Arturo Vidal towards the left-hand side of the box. Sidney Sam raced on to the loose ball and with the utmost composure, slid a shot past Rost and into the net from a tight angle. His sixth goal of the season left a lifeless expression across the face of Hamburg coach Armin Veh.
Veh sent his team out firing on all cylinders after the break as they began the second-half very much on the front foot. Their sustained pressure broke Leverkusen although the 48th minute equalizer also involved a stroke of good fortune. Ze Roberto whipped the corner into the six-yard box, where Vidal beat Westermann to the ball only to slice his clearance into the net via the inside of the post.
However, Leverkusen came back at them once more and took the lead on the hour mark. Guy Demel failed to clear Manuel Friedrich's header and as the Hamburg defense looked at each other, Vidal capitalized to head the ball past Ze Roberto, who was on the post, to restore the visitors' lead.
The lead was extended six minutes later with the best goal of the afternoon. Gonzalo Castro played a defense-splitting pass through to Renato Augusto. The Brazilian winger outpaced David Jarolim before exquisitely lifting the ball over the advancing Frank Rost into the net. Renato Augusto has had his fair share of injury problems but he reminded everyone just what he is capable of.
By now, Leverkusen were rampant and producing one of their best attacking displays of the season. Renato Augusto raced in behind the Hamburg defense on 78 minutes, leaving them for dead before finding the net from a tight angle, albeit with a very helpful deflection off Frank Rost.
This dramatic game was not finished there and just as the home fans began to stream out of the ground, there was a glimmer of hope for Hamburg. Paolo Guerrero suddenly sparked into life and smashed a 25-yard shot against the post. Eljero Elia was the most alert and he blasted the ball over the line despite the best efforts of Rene Adler just one minute after Bayer's fourth goal.
Ninth-placed HSV travel to bottom side Borussia Moenchengladbach for their last game before the winter break whilst Leverkusen, who leapfrog Hannover into second, round off the 2010 league campaign in front of their home fans as they host Freiburg next weekend.
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