Bayer Leverkusen raised doubts about their ability to mount a serious title challenge when they let Karlsruhe come from three goals down to claim a memorable 3-3 draw on Saturday.
With Hoffenheim not in action until Sunday, Leverkusen had a chance to move back on top of the Bundesliga and they seemed certain to take it when Patrick Helmes scored after a few seconds and they improved that lead to 3-0 by the 24th minute.
A lucky deflection at a free kick gave Karlsruhe a lifeline, however, and Leverkusen seemed utterly lost as the home side got back to 3-3.
Hoffenheim, who play away to Hertha Berlin on Sunday, continue to lead the standings with 25 points from 11 games. Leverkusen are second, also with 25 points but having played 12.
Hamburg SV moved up to third on 23 as they held on for a 2-1 win at home to Borussia Dortmund in a bad tempered match.
Bayern Munich slip to fourth on 21 but have the chance to go back above Hamburg when they play at Schalke 04 on Sunday.
Werder Bremen, beaten 3-0 at home to Panathinaikos in the Champions League in midweek, could only draw 0-0 at Bochum and drop to 10th place on 17 points.
Leverkusen had racked up four successive 2-0 wins to move up to second and get people talking about them as dark horses for the title in their first season under Bruno Labbadia.
A return to the top of the table, at least for one night, looked odds on after Helmes strolled through the defence and shot through the keeper's legs with around 30 seconds gone.
Stefan Kiessling made it 2-0 with a header and Michal Kadlec cracked in a free kick and the game seemed to be up.
Leverkusen looked comfortable enough even after Kiessling deflected in a free kick from Antonio da Silva eight minutes before the break but the second half was a different story.
Leverkusen seemed to suffer a crisis of confidence in defence and attack, which became worse after Tim Sebastian converted from a free kick with an hour gone.
An equaliser began to look inevitable and it came when Aleksandr Iashvili headed in 14 minutes from time.