In the end, it just wasn't to be. Union's battle-hardened insticts saw them drag their way back into this pulsating fixture, but, ultimately, a late double in the first half, seemingly out of nowhere, would prove an insurmountable hurdle, despite the magnificent fans packing the Alte Försterei on a typical September  Saturday.

But that they lost seemed so unlikely at first. Oliver Burke’s intentions were clear from the off - on this, his first competitive start for Union. He charged at Bernardo within 10 seconds of kick off, he chased Leon Avdullahu back over the halfway line shortly afterwards. But it was Frederik Rönnow who made the first stop, standing up to Fisnik Asllani when he was played in, inside right, blocking the former Union youth's shot and allowing Union to break up-field. 

They would do so regularly in the first half, always looking to hit their guests with pace and height on the ball.

The new look front line were agitating immediately. If Burke was all speed and pressure, his partners, Ilyas Ansah and Andrej Ilić, would show both their strength and touch; the former somehow back-heeling a ball that seemed destined to go out for a goal kick back for Robert Skov, the latter winning a tussle with Vladimir Coufal. Burke showed his lightning pace again when going past Bernardo on the outside, following Ilić’s flick-on. Burke then put a header wide of the back post following Ansah’s burst and chipped cross from the left. 

Ansah went down in agony under Albian Hajdari’s challenge in the box after seven minutes, with the rain now pouring down, but referee, Tobias Welz, was in no mind to give anything, despite the deafening roars of the crowd. They would have to get used to that.

Having had the better chances so far, and with 18 minutes played, the Alte Försterei, found its voice as one as Burke slipped his man and darted onto another clever long ball, rounding the outrushing Oliver Baumann. He carried on, drifting wide, but his shot, though goal-bound, was cleared off the line by a sliding Bernardo. 

He then hit a volley into the slick ground after a Trimmel free kick came his way after 25 minutes, one that Ilić nudged just wide of the left hand upright. 

Union were largely in control now; tackles were launched into. Skov robbed Vladimir Coufal down near the Hoffenheim corner flag, Hajdari slipped as he battled with Ilić at a high ball, somehow getting the advantage. Khedira left Hajdari in in a heap in the centre circle before Avdullahu caught Ansah as he turned goalwards. Coufal flung himself at a diving header to clear from Trimmel’s lofted cross into the box and  Bernardo managed to block another cross after Burke had sprinted onto Haberer’s clever pass out right. 

Trimmel’s touch with the outside of his heel past Hajdari was a delight, leaving the centre-half for dead, and winning Union’s fourth corner of the half. 

But if all seemed to be going one way, there was a bitter surprise in store for the hosts. With 44 minutes on the clock Leopold Querfeld stood up to Bazoumana Touré in the box. The Hoffenheim player went down, and Welz pointed immediately to the spot. It had come, seemingly out of nothing. After an interminable pause, Kramarić stepped up as Rönnow spread his arms wide, as if standing up to a charging bear, and finished hard and low to the Union stopper’s right. 

Then the roof fell in. Asllani found himself in space out on the right from Lemperle’s pinpoint pass and he looped his finish over the helpless Rönnow. Suddenly, Union were going down the tunnel two down.

Baumgart made no changes at the break, and Burke was quick to try to turn the tide, nipping the ball away after a Hoffenheim short corner and attacking immediately, the ground disappearing under him as he flew. But he was outnumbered as he looked to turn back inside, and the opportunity was missed.

It would only take another minute, however, for Union to score. Folowing chaos in the Hoffenheim box as the ball dropped slowly down towards a grasping, gasping Baumann with both Ilić and Ansah right there. Ansah stood up, careful not to impede the keeper as all hell broke loose around him and bundled the ball over the line. Again, there was a pause as the referee checked, but the goal stood. 

But almost straight away it was 3-1 for the guests, as Khedira’s attempted clearance fell all too easily for Asllani to finish for his second of the game.

Rönnow, fortunately, still had a cool head, despite the volume and the drama and the now pingponging attacks and forays into each others halves. He claimed a difficult dropping ball over the head of the falling Lemperle, before stopping Touré's shot across him at full stretch. 

Union gave their all. Ansah beat Bernardo and smashed across the box. Skov whipped another in with his left for Rothe. Hajdari cleared Rothe's dangerous cross, having sprinted out left, lunging for the ball, and seeing it squirm away off his boot for a corner. Baumann then managed to grab the ball under all sorts of pressure from the looming Khedira. 

Alex Král came on for Haberer with 25 minutes to play, slotting into midfield alongside a Khedira who tried to find Burke with the next attack; the Scotsman’s stepover was neat, but he couldn't find a way towards goal. Union would still yet score another as their renewed pressure told, Tom Rothe hitting a powerful drive from the edge of the box through the crowd with a perfect mixture of frustration, power and technique. He caught it perfectly, and the ball was still rising as it hit the back of the net. 

Union were back in it, and Baumgart made another three changes immediately, taking Burke, Khedira and Ansah off, replacing them with Aljoscha Kemlein, Wooyeong Jeong and Tim Skarke. Skarke was straight into things, skipping onto Trimmel’s clearance, slipping past Bernardo, and clipping a cross towards Ilić that was headed clear at the last. He would flash a volley over the bar with ten minutes to play, though the whistle had already been blown this time.

As Hajdari went down the boos and whistles were now pouring down from the stands, the home fans having felt particularly aggrieved since Touré had writed on the ground following Trimmel's challenge on him. The skipper stood over him, livid at his perceived play acting. 

That roar, however, would be replaced by incredulous silence as Rothe got a straight red card card for a foul on Lemperle in the box. The Hoffenheim player took the resulting spot kick himself, lobbing a Panenka into the net having sent Rönnow away with his jinking step. 

Still Union tried to drag themselves back into things, and Doekhi was a whisker away as he nudged the next Trimmel corner just wide of goal.

With five minutes remaining Baumgart threw on his final substitute, Derrick Köhn, for Skov. Fresh from his first call up for Ghana, the full-back first slashed a volley low and hard into the box, before chasing back to outrun Avdallahu as they raced back towards Rönnow’s goal.

With nine minutes added, Král charged on, forcing a good stop from Baumann, following it up as he stopped Ilić converting the loose ball. Skarke couldn’t quite get on the end of the Czech’s next pass up the middle, nor could Jeong as he headed the ball past a flailing Baumann, but was muscled away from danger.

Kemlein, floored by Wouter Burger, looked to take the free kick himself, but Baumgart, at the very edge of his area, ordered him into the box. Jeong, then with a final throw of the dice, beat one, but was again bustled off the ball by Max Moerstadt.

At the end the Union players were stood in the now empty penalty box in front of the Waldseite for an eternity as the crowd stayed to a man, singing, cheering, willing them on for the next round, the next battle. They'll dust themselves off and focus on the next week's trip to Eintracht. 

"We simply have to do a better job of preventing goals like that – we want to work harder on that now. Of course, I'm happy about my goal, but a point or even three would have been more important to me. The positive thing is that we created more chances, and we can build on that. At the end of the day, we attack as a team, defend as a team – and as a team, we conceded too many goals today to win the game." 

"Unfortunately, with the two penalties and the other goals we conceded, there were too many mistakes in our game today. Mistakes happen in football, they are part of the game, but conceding four goals at home is simply too many. We had a lot of good chances in attack, we were more courageous – and that's exactly what we want to take with us into the coming week of training." 

"Of course, there were individual things we need to do better today. Despite all that, I'm satisfied with my team's performance. The double blow before the break was something the team had to grapple with. Nevertheless, we always came back after the setbacks – and that's exactly what we want to see. Of course, we want to step it up a notch, both offensively and defensively, to win games like this in the end."