Before kick off, the flags came out, either on poles borne by kids dressed in black or laid out on the pitch by more of the same. The anthems played, first the official league one, loud and trying too hard. Then Nina Hagen’s, powerful and bellowed and meant to a word. The crowd swelled. Nerves jangled. Some cast their minds back to the Fritz Lesch Sportplatz, to a couple of hundred people dotted along the earth bank that served as a grandstand and as a playground for bored kids. Lisa Heiseler was there back then, of course, and now here she was, the world watching, 17,023 in her home, deafening as her name was read out, as she led her side out to play FC Bayern in the Bundesliga season opener.

But though pride filled the stadium, it wasn’t enough. Against a side like Bayern, it rarely will be. Marie-Louise Eta spoke after the final whistle of how she was especially happy at how her players had reacted to going two down just after the break. “We all wanted a different result, but there’s much to be happy about,” she said. Frankly, she nailed it. This side will go a long way yet. Jose Barcala, Eta’s opposite number, was effusive too. He called Union “unique”, saying that their success was just “a matter of time”.

Kick off was dominated by the sound of the stadium roaring as one. Well, that and the sound of a thousand tifo balloons bursting like it was Chinese New Year. It was stopped only by the first intervention of the day, Jella Veit stepping up to tackle Kim Dallmann on the edge of the Union box.  

Eta’s plan was clear. Soak up the pressure, keep your structure, time your tackles, and then break at pace. Dallmann had the first strike of the day, but flashed wide of Cara Bösl’s goal after a stray pass came her way, before Eileen Campbell came much closer, suddenly played in by Lisanne Gräwe’s perfectly weighted pass up the line. The Union fans held their breath as she raced free, taking a touch or two before seeing her shot squeeze just the wrong side of Ena Mahmutovic’s right-hand upright.

And when Jovanna Damnatovic seemed to be into the box, a chance rearing its head, Heiseler was there, chasing back to clear the ball she had nudged that way, standing tall before going to ground at just the right moment. But that was nothing. Tomke Schneider dismissed the former Champions League winner like she wasn’t there at all, brushing her aside like an annoying younger sibling.

Eta had said during the week that Union needed to be courageous, and it was to be seen in Bösl’s pass out to Veit on 12 minutes, up the middle, low and hit just outside her box. They were willing to risk sticking to their principles here. As it showed when Leela Egli chased down Glodis Viggosdottir; when Schneider forced a diving stop from Mahmutovic having cut in onto her right; when Jill Janssens stopped the excellent Klara Brühl in her tracks.

Their solidarity showed, too. Schneider, having dispossessed Stine Ballsager, was met with slapped palms from Samantha Steuerwald, Egli and Bösl.

But after 25 minutes the hosts took the lead the only way they could. Steuerwald was certain she had won the ball when coming out to slide into a tackle just outside the box, and couldn’t believe it as referee, Miriam Schwermer, called the foul. In the face of deafening whistles, Brühl did what she does, sweeping the ball high and hard, past Bösl’s dive and inside the back post.

Still, Union stuck to their plan, despite the clear upswing in Bayern’s confidence following the goal. When patience was needed, Gräwe showed it, moving the ball back and to the right; when it needed to go, then Veit lashed it miles upfield. Their guests were reduced to potshots and Naschenweng dragged hers wide of Bösl’s post when she got a sighter from range.

Union won three corners in succession, two hit to the near post by Lia Kamber – who was given barely a sniff of space to work all day -  the last high and into the middle by Heiseler. Then they broke at lightning pace up the left, with Gräwe and Egli playing a long one-two up the line, a near-certain next corner only rescued at the last by the lunging Mahmutovic.

Courageous? Gräwe’s tackle on Pernille Harder was impeccable as the break neared. They’d go down the tunnel chests puffed out.

Union came out unchanged after the break, but Veit’s challenge on Dallmann in her own box was a sign that Bayern were going to try and seize an early chance. They did just that a minute later, when Harder marched into the box again, and bent her shot past a helpless Bösl, diving to her left. It was a hammer blow, and would prove decisive.

Union came back. Egli couldn’t tuck Janssen’s cross away with her first touch and ended up spinning around, looking for a chance to get her shot away. Campbell nipped in to dispossess Naschenweng. Kamber tried to flick Janssens’ ball inside over the top of Magdalena Eriksson with the outside of her boot in the direction of Heiseler.

Bayern weren’t to roll over though; they started to dominate their hosts. They are a superb side – in the pre-game warm-ups, they focussed on passing movements, using the whole team - and at times Union were clinging on. Bösl tipped Bernadette Amani’s vicious drive over the bar, just after Steuerwald shepherded Harder away from goal, the threat of a shot always there. Janssens got in the way of Momoko Tanikawa’s effort. Bösl held two more from Harder and Damnjanovic.

So, with just over 30 minutes to go Eta made her first substitutions, bringing Sophie Weidauer and Naika Reissner on for Heiseler and Veit. It was an attacking change, a sign of intent, but they had barely been on the pitch for 10 seconds when Viggosdottir made it 3-0, sweeping her shot home from a couple of yards out following a free kick on the edge of the box.

Reissner was set free almost straight afterwards though, as Eta reacted quickest to the ball going out of play, laying it off to Schneider who took the quickest of throw-ins up the line. But as Union threatened, Schwermer called them back, presumably for Eta’s quick-thinking. The Union head coach was livid, and at the next opportunity handed the ball to Schneider, her actions dripping with sarcasm.

Buoyed by the crowd and the sense of injustice Union went at their guests with renewed vigour. Heiseler’s replacement as captain, Steuerwald, flashed her shot just over after the next corner; Campbell strode forwards; Egli was certain she’d won a corner off Naschenweng, disbelieving when it wasn’t given. She would get booked with 20 minutes to play for a shove on Harder, her frustration showing. Egli would be substituted shortly afterwards for Nele Bauereisen, with Judith Steinert coming on for Campbell as they shifted to a back three.

They got the goal they more than deserved after 78 minutes, with Reissner charging into space and finding Janssens out right. Though it seemed she had taken a touch too far, her cross hung in the air, teasingly, headed back across goal by Weidauer where Bauereisen met it, headed past a Mahmutovic who looked like she was trying to swim through treacle to get to the ball as it crossed the line.

The Alte Försterei erupted. Delirium. Bedlam. And they sung Zombie nation as Union attacked again and again. They attacked through Reissner and Weidauer on one side, through Janssens and Bauereisen on the other. And when Barabara Dunst hoicked another Janssens cross away for a throw, it felt like it was the perennial champions who were on the ropes.

That Sophie Proost made it 4-1 on the stroke of 90 minutes mattered little. It was a fine finish, hit on the turn, through the eye of a needle, but by this point the Union fans were consigned to their defeat. But still they sung. And still they cried out as Reissner made one final burst, then as Bauereisen flashed a wonderful, skidded volley just over the bar. It mattered little.

At the final whistle the skies opened, but it wasn’t the rain that kept the masses in under the roof of the Alte Försterei. They stayed to sing and show their pride as the players made their final rounds of the pitch, dejected, but knowing that they had made one hell of a statement.

They may have lost today. But as Barcala pointed out, they’ll certainly take some stopping. 

“I am a bit disappointed with the result, it doesn’t reflect our performance today. We held our ground well and allowed very little. The atmosphere was insane today and I had goosebumps during the warm-up,” summarized Samantha Steuerwald the match.   

“We held our ground very well against a top team, but of course we are disappointed. We will now have to analyze the goals conceded. I am glad about my goal, but I would have wished that it had a greater value,” said Nele Bauereisen after the match.   

“Essentially, the victory for Bayern München is of course justified. We knew that we were playing against a very good team today. Of course, we are still disappointed because there were one or two goals against us too many. We had good phases in the game and it didn't feel as pronounced as the result suggests now,” explained head coach Marie-Louise Eta after the start of the competitive match.