Berlin: Ten-man Hanover inflicted a second straight 2-1 defeat on champions Borussia Dortmund on Sunday thanks to two late goals in two minutes with Ivory Coast striker Didier Ya Konan netting the winner.
Dortmund, who were beaten at home by Hertha Berlin last Saturday, suffered a third loss against two wins in six games this season, leaving Jurgen Klopp`s young team in 11th place.
Japan winger Shinji Kagawa put Dortmund 1-0 up on 63 minutes, but Hanover fought back and snatched victory in the dying minutes.
Captain Karim Haggui rose highest from a corner and crashed home his header on 87 minutes and with Dortmund reeling, Ya Konan fired home from close range to give Hanover their third win of the season on 89 minutes.
In a frantic finish, Hanover`s Poland striker Artur Sobiech was shown a straight red card for tackling Dortmund`s Brazilian midfielder Antonio da Silva from behind just seconds before the final whistle.
It was the fifth red card of the weekend to set a new Bundesliga record.
"We just kept believing in ourselves," said delighted Hanover goal-scorer Haggui.
Having now lost to Hoffenheim, Hertha and Hanover, Klopp`s side are struggling to defend their title and with six games gone are already six points off leaders Werder Bremen.
"It was my fault for their first goal," admitted Dortmund defender Neven Subotic.
"We dominated the game over 85 minutes, then made one mistake and everything changed.
"Because of five minutes, we are left to travel home with a bad feeling."
Bayern Munich have the chance to go back to the top if they beat Schalke 04 in Gelsenkirchen on Sunday evening after 10-man Bremen went top on Saturday thanks to a 1-1 draw at Nuremberg.
Bremen had Germany goalkeeper Tim Wiese sent off after just 17 minutes as the 29-year-old was shown a straight red after a rugby-style tackle on Nuremberg striker Christian Eigler, who was through on goal.
Werder then took the lead when Turkey midfielder Mehmet Ekici scored against his former club just seven minutes later, but the hosts levelled on 62 minutes with a late header from defender Philipp Wollscheid.
The point leaves Bremen top on goal difference, and level on 13 points with Moenchengladbach, who kept up their impressive start to the season with a 1-0 win at bottom side Hamburg.
Brazil-born Belgium striker Igor de Camargo got the crucial goal with a header on 66 minutes to knock Bayern down to third.
Hamburg remain rooted to the bottom of the table with one point from six games as pressure grows on coach Michael Oenning.
Having lost 2-0 at Chelsea in their opening Champions League game on Tuesday, Bayer Leverkusen were dismantled by Cologne as Germany striker Lukas Podolski and Slovakian forward partner Milivoje Novakovic ran riot in a 4-1 victory.
Kaiserslautern got their first win of the season when they beat Mainz 3-1 while Hoffenheim earned a 2-1 win at home to Wolfsburg to go fourth.
Bundesliga new boys Hertha Berlin and Augsburg, who both won promotion from the second division last season, played out a 2-2 draw at Berlin`s Olympic Stadium.