Through the peaks and troughs of Bayern Munich’s season, the sniping and the setbacks and the scintillating form of Bayer Leverkusen, one basic principle has remained largely unchallenged. That once Thomas Tuchel’s side got a whiff of their 12th consecutive Bundesliga title, the old muscle memory would kick in. That they would eventually show their true selves when it mattered most, in games like this. And they did; just not remotely in the way anyone expected. For this was not simply a defeat but a humbling, not just three crucial points in the title race but an attack on Bayern’s very identity. Bayern were outclassed by a quicker, hungrier, more creative Bayer Leverkusen side. Meanwhile Tuchel was out-thought by Xabi Alonso, who cemented his status as the most promising young coach in the sport with a dizzyingly imaginative selection, cute tactical flourishes and smart use of the bench. The gap at the top of the league is now five points, and yet for the coming days and weeks most of the talk in Germany will be of Bayern implosion, Bayern crisis, Bayern fume. “To be honest, I’m pissed off,” fumed Thomas Müller in a furious post-match television interview. “To quote Oliver Kahn: what’s missing is balls. It’s OK to feel pressure, but there needs to be energy and freedom. It’s not just about the coach. Sometimes we have to speak about the players.” And if Bayer Leverkusen always believed, then perhaps this was the moment when the rest of us could too. Josip Stanisic opened the scoring, Álex Grimaldo scored the game-clincher early in the second half, Florian Wirtz and Granit Xhaka were sensational in midfield, and Jeremie Frimpong spectacularly sealed the points in injury time. But what distinguishes this Leverkusen team is how little they rely on moments of individual quality. They defend and attack as a unit, interchangeable pieces running quirky angles with relentless pressing. Here Alonso went without a recognised striker. Amine Adli played as a false nine complemented by Nathan Tella on the right. Stanisic over Frimpong was another surprising call. Alonso talks a lot about flexibility, and this performance – artistic and elusive, rehearsed and resilient in all the right places – is why. The result was a game with all the textural quality of a David Lynch movie: thick with intrigue and red herrings, strange motifs and hidden layers of meaning. Why were fans throwing sweets onto the pitch? Why was Stanisic the only player on his team not celebrating his goal? Why were Bayern’s full-backs playing on opposite sides? And why was there a home fan dressed as the pope? Some of these questions were easier to answer than others. The sweets, which delayed kick-off by eight minutes, were part of a long-running protest by fans across Germany at a proposed deal selling off a stake in the Bundesliga’s media rights to private investment. The fancy dress was for Karneval weekend. Stanisic is currently on loan from Bayern. And perhaps Tuchel’s decision to play Sacha Boey at left-back was an attempt to counter the pace of Frimpong, who ended up not starting. And so Bayern were beaten not just in practice but in theory. Perhaps one of the reasons their defence looked so uncertain was that it was never entirely clear what they were trying to defend. Perhaps one of the reasons Harry Kane was so anonymous was that Bayern didn’t have the faintest idea how to get him into the game. The result was three goals of varying degrees of head-loss. The first for Stanisic came when Bayern completely went to sleep for the second phase of play after a Manuel Neuer save. The second for Grimaldo came from a simple give-and-go, Aleksandar Pavlovic failing to track the run. The third came deep into injury time, with Neuer still up for a corner (why?) and Frimpong brilliantly curling the ball in from about 30 yards. Frankly the margin could have been even wider. Bayern barely produced a decent chance all night. And of course this is still only February, and Leverkusen have never won a title in their history, and nothing has been sealed yet. But if it is still too early to call time on the era of Bayern dominance, then it has never felt more precarious.