A goal from Mladen Petric shortly before half time was enough to decide the game in the northern Germany's side favour and take them to the top of the table above Bayern, who had more than enough chances to level and even win the game.

"The ball just didn't want to go in," said Bayern coach Jurgen Klinsmann.

"We are now disappointed and angry. We had expected to get something here.

"We had enough chances to correct the Hamburg lead, but we did not put them in, which is why we are left empty handed."

Hamburg's victory opens up the title race which, following Bayern's overwhelming 5-1 win over Stuttgart in the cup last week, had seem set to become a one-horse race.

Today, Hertha Berlin get the chance to overtake Bayern too while Hoffenheim can move three points above them at the summit.

"HSV are in the race for the title, if they weren't before tonight," proclaimed Bayern chairman Karl-Heinz Rummenigge.

For Hamburg coach Martin Jol, victory over his side's southern rivals was "the highlight of my time in Hamburg."

"That was an incredible game," he continued. "We could have scored five or six goals and Bayern had enough chances to score too."

However match-winner Mladen Petric was not getting carried away.

"We have just won the first game of the second half of the season. It is too early to talk about the title again now."