Bayern Munich were stunned on Saturday afternoon, as they fell to a 4-2 mauling at the hands of mid-table VfL Bochum - who they beat 7-0 at the Allianz Arena earlier in the season.
In succumbing to that truly shocking defeat, Julian Nagelsmann's side passed up the opportunity to at least momentarily move 12 points clear of Borussia Dortmund, who travel to Union Berlin on Sunday, at the league summit.
In what was an utterly dominant and devastating performance, Bochum's creativity, ruthlessness and desire completely outweighed a severely disappointing Bayern collective, who deservedly fell to their heaviest Bundesliga loss of the season.
And given the scoreline, you'll be unsurprised to hear that it was Bochum who started on the front foot, worrying their visitors with several promising offensive phases of play in the opening stages. At this point unphased, however, it took Bayern just one opportunity and nine minutes to forge the opening goal through a typically sweeping move.
Stretching his neck to nod Thomas Muller's cross back across goal, Kingsley Coman picked out Robert Lewandowski in the six-yard area, before the Pole managed to impressively contort his body and bundle the ball into Michael Esser's bottom corner from close range.
A bright response from the hosts was forthcoming, however, as Christopher Antwi-Adjei deservedly equalised with his first Bundesliga goal for Bochum just five minutes later.
Taking advantage of Bayern's attacking formation and lack of bodies in defensive areas, the hosts embarked on a quick counter attack that was rounded off by the Ghanaian winger, whose composed take and delicious curling finish from 18 yards gave a sprawling Sven Ulreich no chance.
Bochum's fearless and threatening first-half performance was rewarded even further in a jaw-dropping seven minutes leading into the break.
First came Jurgen Locadia's penalty in the 38th minute, rather harshly awarded after Dayot Upamecano handled Elvis Rexhbecaj's cross in the area - from very close range and in what appeared to be a natural position, it must be noted. That was soon forgotten, though, when just two minutes later the home fans were sent into raptures when Cristian Gamboa's stunner pulled them two goals ahead.
The right-back picked the ball up on the right-wing, before nutmegging his way past Coman, surging towards the penalty area and unleashing a rocket into Ulreich's top corner from the edge of the box. Quite incredibly, however, the hosts weren't finished with their first-half rout.
Gerrit Holtmann was next to get in on the act, picking up a loose ball on the left corner of the penalty area before unleashing a sensational, floating, bending strike that nestled perfectly into a helpless Ulreich's top corner.
Bayern fans must have been pulling every single follicle out of their heads just three minutes into the second half, at which point Bochum had already had the ball in the back of the net twice. Two offside calls, however, denied Maxim Leitsch and Antwi-Adjei lead-extending goals.
It was pretty much confirmed to be one of those days for Nagelsmann's side when, in the 51st minute, Lewandowski passed up a one-on-one opportunity. Put clean through on goal, the striker rounded the goalkeeper before seeing his measly effort cleared off the line by a back-tracking Armel Bella-Kotchap.
Even so, Bayern's number nine gave his side a slither of hope as he managed to eventually pull one back with 15 minutes remaining. With the ball breaking his way in the opposition penalty area after a free-kick, Lewandowski set himself before powering in a scissor kick and urging his colleagues back to their own half for the restart.
The Bundesliga's top marksman was subsequently denied a hat-trick as his free-kick connected flush with the crossbar, but his previous urgency generally failed to translate itself into the visitors' performance for the remainder of the match.
Bochum were, therefore, able to stoically see out the contest to the soundtrack of a raucous, bouncing fanbase who were basking in a historical moment for their football club - you just love to see it.
In truth, a tenth successive Meisterschale still looks an inevitability but they'll have to improve pretty immediately as they face RB Salzburg in the first leg of their Champions League round of 16 tie on Wednesday night.
Bayern Munich player ratings
1. Goalkeeper & defenders
Sven Ulreich (GK) - 3/10 - This is going to sound suspect, but he genuinely didn't have much hope with any of Bochum's strikes. Was actually otherwise solid.
Benjamin Pavard (RB) - 2/10 - Just so mediocre and should have got closer to Holtmann before he sent Bochum fans into a euphoric state at the end of the first half.
Dayot Upamecano (CB) - 1/10 - Started strongly but fell apart completely before being sacrificed at the interval. 45 minutes to forget, to really forget.
Niklas Sule (CB) - 2/10 - Looked sluggish for the majority, notably looking half asleep when facing up to Antwi-Adjei for Bochum's equaliser. If BVB think his arrival is going to resolve all of their defensive issues, they've got another thing coming.
Lucas Hernandez (LB) - 2/10 - His performance on the back foot was as useful as a chocolate teapot.
Joshua Kimmich (DM) - 2/10 - Slightly more imposing after a change of formation at the break, but was completely overpowered by Bochum's blistering attitude and intensity.
Thomas Muller (AM) - 2/10 - Unsurprisingly pivotal to the early opener but completely waned thereafter. Almost non-existent before being replaced after an hour.
Leroy Sane (AM) - 1/10 - Possibly his worst performance of the season - just couldn't get into the game and make his undoubted quality felt.
Serge Gnabry (RW) - 2/10 - Showed some nice, smooth and skilful touches although all too often failed to make them count in a penetrative and impactful manner.
Robert Lewandowski (ST) - 5/10 - Good finishes to notch both of Bayern's goals - but should have had more and, otherwise, was largely absent.
Kingsley Coman (LW) - 5/10 - Proved Bayern's liveliest and most threatening presence, always showing a desire to drive at his opposition and doing well to assist his side's first. Even he was pretty rubbish, though.
Corentin Tolisso (CM) - 2/10 - Looked as though he'd have rather stayed on the bench - and who could blame him?
Eric Maxim Choupo-Moting (ST) - 2/10 - He came on? Are you sure?
Marcel Sabitzer (CM) - N/A