Hansi Flick admitted his Bayern Munich team were tired and ripe to be punished after a 2-1 defeat at Mainz delayed title celebrations.
Chasing the win that would have clinched a ninth successive Bundesliga title, Bayern gave a lethargic display and a last-gasp goal from Robert Lewandowski was as much as they deserved.
Mainz seized advantage as the one-time strugglers took their points tally to 28 from 16 games under new head coach Bo Svensson, soaring five points clear of the relegation zone.
Bayern boss Flick said: “We all know that just as the team has often shown its quality, something like that can happen. It’s a shame we couldn’t take the step today.
“But you have to understand that the team is tired. We were too harmless.
“We want to win every game, that was also the case today. We didn’t perform well, you have to accept that.
“The team have many minutes in their legs. We just weren’t strong enough.”
First-half goals from Jonathan Burkardt and Robin Quaison put Bayern in a tangle, and the stoppage-time reply from Lewandowski, returning from injury, came too late to spark anything more.
Lewandowski now has 36 goals for the season, meaning he trails Gerd Muller’s Bundesliga record by four with three rounds of games remaining.
His goal in Saturday’s game was a gift rather than the result of any great personal endeavour, with a poor defensive header leaving Lewandowski the task of stroking the ball past cruelly exposed goalkeeper Robin Zentner.
Bayern slipped to a first Bundesliga defeat at Mainz since 2011, having won all eight of their away games against the 05ers since that 3-2 loss a decade ago.
Manuel Neuer was unusually at fault for the third-minute opening goal, getting in the way of the powerful shot from Burkardt but only being able to divert it into the corner of his net.
“I wasn’t blinded by the sun,” said Neuer, according to TZ.
“The ball was close to [David] Alaba, I couldn’t see it well. I tried to put my arm up, I was unlucky.”
Bayern have been hit by a Champions League quarter-final exit, the announcement from Flick that he wants to be released from his contract at the end of the season, and criticism from fans aimed at Hasan Salihamidzic.
That may have been a contributing factor to Saturday’s below-par effort, but Neuer pointed to Mainz’s qualities.
“We weren’t surprised,” said the goalkeeper. “It was clear that they went into the game with a high level of motivation. Our body language was bad.”
Bayern could still be crowned champions this weekend, but RB Leipzig would need to lose to Stuttgart on Sunday.
“I would have preferred to have got it done ourselves,” said Neuer. “The defeat hits us hard after the last few weeks.”