Champions Bayern Munich crashed to a 3-2 loss at VfL Bochum on Sunday for a third straight defeat in all competitions, dropping eight points behind league leaders Bayer Leverkusen.
The Bavarians, who had Dayot Upamecano sent off for the second consecutive match after his dismissal in Wednesday's Champions League loss to Lazio, showed no real game plan with coach Thomas Tuchel now facing mounting pressure.
His team had lost last week's big league match against Leverkusen and suffered a 1-0 defeat to Italy's Lazio in their round-of-16 first leg.
"Now (the title) does not look very realistic," Tuchel said. "But last season we believed until the end and we were rewarded. So we will keep working at it."
Referring to the pressure on him following his team's third loss, he added: "That happens after every defeat.
"The 'how' we played is key. The 'how' was good today and that's why today's 90 minutes are very different from the second half at Lazio or the game at Leverkusen."
Bayern were desperate to bounce back and did get a 13th-minute lead when Jamal Musiala drilled in from a tight angle as early pressure paid off.
Bundesliga top scorer Harry Kane should have made it 2-0 but he missed a sitter in front of goal in the 19th, firing wildly over the bar before the game was interrupted.
Fans started throwing tennis balls on to the pitch in protest at a planned foreign investment in the Bundesliga.
Such protests have increased on recent matchdays with almost every league game on Saturday and Sunday having been briefly interrupted.
The 15-minute stop in play did wonders for Bochum's game, with Takuma Asano completing a quick break to stun Bayern with a 38th-minute equaliser.
They completed their comeback before the break when Keven Schlotterbeck headed in a corner in the 44th.
Kevin Stoeger's 78th-minute penalty put the game to bed after Upamecano was sent off for elbowing an opponent in the box, with a second booking.
Kane tapped in his 25th league goal in the 87th but it did little more than inject some late drama, with Bochum holding on to the three points.
There was also drama after the final whistle with Bayern's Joshua Kimmich leaving for the changing rooms after a heated verbal chat with Bayern assistant coach Zsolt Loew.
Bayern, chasing a record-extending 12th straight league title, are in second place on 50 points, eight behind Leverkusen, while Bochum moved up to 11th on 25.
