Bayern Munich conceded a late equaliser and lost Franck Ribery to injury in a 1-1 draw at VfL Wolfsburg on Saturday which left the champions 16 points off the top.
The result could spell a premature end to their title hopes after 18 games but defeats of second-placed Mainz 05 and Bayer Leverkusen, in third place also on 33 points, mean Bayern are only three points off the Champions League spots.
Bayern took an early lead when Wolfsburg keeper Diego Benaglio raced out of the box only for his attempted clearance to hit Thomas Mueller's leg and roll into the goal.
Both sides missed first-half penalties and Bayern lost Ribery, who limped off in the 17th minute with a knee injury to be replaced by Arjen Robben in his first appearance of the season.
Sascha Riether gave troubled Wolfsburg coach Steve McClaren something to smile about when he tapped in Marcel Schaefer's low cross for an 86th minute equaliser.
Bayern are in fifth place on 30 points, way behind leaders Borussia Dortmund on 46. Dortmund stretched their lead to 13 points with a 3-1 win at Bayer Leverkusen on Friday and on Saturday Mainz failed to make inroads, slumping to a 1-0 defeat at VfB Stuttgart.
Werder Bremen returned to winning ways, beating Hoffenheim 2-1 with a last-gasp goal from Torsten Frings to climb up to 12th spot on 22 points.
Last-placed Borussia Moenchengladbach grabbed a valuable 1-0 win at Nuremberg to move up to 13 points and close the gap with relegation-threatened Cologne. Schalke 04 take on Hamburg SV later on Saturday.
It was supposed to be the start of Bayern's battle for the championship and early on it looked to be exactly that when Mario Gomez rattled the crossbar and Mueller gave them the lead.
But Philipp Lahm failed to convert his 21st minute penalty, hitting the post as the hosts had no answer to Bayern's aggression.
But they clawed their way back late in the first half and even won a penalty in the dying seconds. Newly established first choice Bayern keeper Thomas Kraft did well to palm Grafite's spot kick onto the bar.
Robben's entry added pace to the game of Bayern, who largely dominated in the second half but failed again to convert any of their half dozen chances.
They were punished when Schaefer left Bastian Schweinsteiger standing on the left and cut back into the box for Riether to slot home.