Bochum extended its unbeaten start to the season and ended Hamburg's 100 per-cent record through a 2-1 victory at the Ruhr Stadium on Friday.
Stanislav Sestak put Bochum home side ahead on the stroke of half-time and substitute Daniel Imhof made it 2-0 seven minutes from the end.
Hamburg, who had Vincent Kompany sent off on the hour mark, earned a lifeline through Rafael van der Vaart's penalty in the 86th minute, but it was Bochum which secured the win to take the club to the top of the Bundesliga table.
In a game billed as a top-of-the-table clash, neither side was leaving much room for their opponents.
While Bochum did all the early running, it was coming up against a strong, disciplined Hamburg side eager to maintain its perfect start to the season.
Hamburg also came close to breaking the deadlock with its first attack 10 minutes before the end of the first half.
Mohamed Zidan tricked his way through three Bochum defenders, but shot into the side-netting with Van der Vaart free in the middle.
With the visitors beginning to impose themselves, it was the home side which would probably have been happy to hear the half-time whistle, but it was delighted it did not come punctually.
In the first minute of added time, Sestak swept a loose ball in from 10 yards after Nigel de Jong lost out in an aerial challenge with Joel Epalle.
It was the first goal Hamburg had conceded all season, and Sestak's second goal in as many games.
Tommy Bechmann led the charge towards a second goal early in the second half setting up Philipp Bonig, who failed to finish the move.
Hamburg's task of recovering was made more difficult when Kompany received his marching orders for a foul on Bechmann.
Bochum made the game safe in the 83rd minute when substitute Imhof received a 25-yard pass and unleashed a powerful shot beyond Frank Rost into the top right-hand corner of the goal.
Hamburg pulled one back when Sestak felled David Jarolim inside the penalty area and Van der Vaart converted what proved to be a mere consolation.
German Bundesliga
VfL Bochum 2 (Sestak 45, Imhof 83)
Hamburg SV 1 (van der Vaart 86p)