1. FC Union Berlin lost 1-0 to the runaway table-toppers Bayer 04 Leverkusen, but the result masks a superb performance, particularly in a second half that saw them already down to ten men following Robin Gosens’ red card at the end of the first half. His second yellow was the catalyst for a few wild minutes that culminated in Florian Wirtz’s converted, if contested, penalty kick.

1. FC Union Berlin: Rönnow – Trimmel (62. Juranović), Doekhi, Vogt, Leite, Gosens – Tousart, Khedira (62. Laïdounï), Schäfer (62. Král) – Aaronson (78. Hollerbach), Vertessen (46. Kaufmann)

Bayer 04 Leverkusen: Hrádecký – Kossounou, Tah, Hincapié– Tella (79. Frimpong), Andrich, Xhaka, Grimaldo – Hložek (32. Adli), Iglesias (66. Boniface), WirtzThe starting XI

Nenad Bjelica had spoken during his press conference on Thursday of the need for his players to be at their absolute limits against a side unbeaten this season. For them to concentrate, to fight and above all to take their chances. But if Xabi Alonso made five changes to his side, he had made just the one from his last two line-ups with Andras Schäfer returning to his spot as the fulcrum between a midfield anchored by Rani Khedira and Lucas Tousart, allowing Brenden Aaronson to join Yorbe Vertessen ahead of them.

Accordingly, at the back they were as they always have been when he’s had the luxury of all his players fit. Frederik Rönnow was in goal behind Diogo Leite, Kevin Vogt and Danilho Doekhi. The wingbacks were Robin Gosens, on the left, and Christopher Trimmel on the right.

Attendance: 22.012

Goals:  0:1 Wirtz (45. +8.)

A wild half, capped by Gosens’ red, and Wirtz’s converted penalty

If the final whistle was greeted with the roaring cheers of pride at an Union performance that was as brave as it was doomed, it started with the jeers at Bayer Leverkusen’s decision to turn the tables and let Union kick off into the Waldseite.

Maybe, however, that simple, single decision would be a major factor in the league leaders taking home the three points. For if they had their backs to the Ultras at the end, as they clung on to a single goal lead, despite having been a man up for the whole of the second half, and Frederik Rönnow appeared for the second time for a corner in their box…

As a wise man once wrote, God only knows.

But that was all to come. The guests started with typical, clinical precision. Granit Xhaka, Piero Hincapie and Florian Wirtz exchanged neat passes around the right-hand edge of the Union box, before Borja Iglesias had the first shot - though it wasn’t on goal. He scuffed it across Rönnow, the ball rolling wide of the post. Trimmel though was as if out to prove a point.  He was superb, haring in on Hincapie immediately, as the ball lay in the corner, losing possession but making a point.

Leverkusen’s intricacies were only met with a doubling and redoubling of Union’s efforts. Aaronson and Vertessen were already chasing miles and miles up top before Schäfer, too, made his own point when he tackled Adam Hlozek, having tracked him from the halfway line. If that was a brilliant piece of determined chasing, Khedira’s tackle on Alejandro Grimaldo was a masterpiece, a perfectly timed piece of controlled aggression. Trimmel nudged him off the ball and into the hoardings a moment later. The Spaniard was getting bullied out on the left.

But Union needed to be on their guard. After eight minutes Wirtz flickered, making his way towards the box only to be brought down by Gosens. The temperatures rose as the players all suddenly seemed to come together, and Gosens got a yellow card; one he would come to rue in time. For the free kick only Vertessen wasn’t in the box, dragging Hincapie back towards the centre circle. But he wouldn’t be needed, Rönnow dived to punch Grimaldo’s direct shot away to his right.

Rönnow was brilliant, on top form again. He made a beautiful save from Iglesias’s header after quarter of an hour, his reflexes as sharp as ever, flicking his hand up to put the goal-bound shot over the bar. But as Leverkusen dominated the ball, moving it with a certain grace and incisiveness, Union were holding on, waiting for the chance to spring into the break that Aaronson and Vertessen were constantly ready for, like cats on edge, ready to pounce. It took the full weight of the former Unioner, Robert Andric, to stop the latter after 25 minutes, as Jonathan Tah had to grapple him off the ball in the centre circle a minute later.

Meanwhile, Union held firm, patient at the back, and man-of-the-match Leite’s shepherding of the dangerous Nathan Tella out on the Leverkusen right was superb. Then Union stepped up, Aaronson finding Vertessen with a beautiful ball up the right, and suddenly there they were around the box, Gosens, Tousart, Schäfer, circling, trying to find a way through the crowd.

As Hlozek went down hurt with half an hour played, to be replaced by Amine Adli, Bjelica, sharp as a tack in blazer and trousers, called his players together. But he only had to confirm to them that they needed to keep going. The plan was working, and a couple of minutes later many thought they had made the breakthrough when Gosens flicked Trimmel’s corner just wide of the left hand upright.

Tousart was excellent, never allowing any away player to settle on the ball for a moment. He cleared the free kick he had given away from within his own box, before Rönnow took Grimaldo’s speculative ball with studied imperiousness, puffing out his chest, holding the ball with both hands above his head. He made another stop from Andrich later, this one far trickier, as the ball bounced awkwardly in front of him as he dived to his left, jumping up off the turf like a cobra in strike.

Vertessen shot over following a lovely move started when Trimmel robbed Grimaldo - he tormented the Leverkusen left back - via Aaronson, Khedira and Schäfer. Union were now growing in confidence. Trimmel covered half the pitch to outrun Grimaldo with the last embers of the half flickering, the burning sun on his back, covering the ground like a man 20 years his junior.

But if Union thought that was that, there was a decisive twist to the game yet to come. Gosens got a second yellow on the stroke of half time for a late lunge on Tella, and it led to chaos. The resulting free kick was hit into Union’s box, striking the post from Hincapie’s shot, pinballing around before Odilon Kossounou somehow crashed it past Rönnow. Players from both sides poured around the referee, Benjamin Brand, as a hand had been seen in amongst the melee.

They stood around for what felt like and age as the video assistant mulled it over.

With the penalty given, Rönnow handed Wirtz the ball. He spat on his gloves and pointed to his right, daring the young German international to go that way. Wirtz didn’t blink and shot that way. Rönnow went the other.

“Of course, the minutes before the break were decisive,” said captain Trimmel, after the final whistle. “It's already very difficult to play against Leverkusen with eleven men on the pitch." He was joined by Aaronson, however, in making sure not to lay the blame entirely at the feet of Union’s left-back.

It was the worst possible ending to the half that Union could have imagined. They were now a goal, and a man down.

Ten man Union give their all, but can’t come back

Bjelica started the second half off by bringing on Mikkel Kaufmann for Vertessen, presumably thinking his height and strength would be needed as opposed to the Belgian’s fleet of foot. It changed the shape of the game as well as the pace of it; now Union were pegged back, and Rönnow had to make another sharp stop from Iglesias’s stabbed attempt from two yards out.

Union would need their stopper to be at his best, and he was. He made another from Tella after Adli’s clever drag-back and Andrich’s simple pass out right.

Tousart won a corner, implausibly, chasing Kossounou all the way towards Khedira’s speculative ball over the top. Khedira then won another, himself, over on the other side a moment later, from which Schäfer won a third, his shot bouncing off Tah in the box.

Union then won a throw, out on the right. Aaronson was ready to take it, quick, but Khedira, the old hand, told him to wait, to take his time, to enjoy the moment of pressure on their guests. For soon enough the ball would be back in Union’s half, with Bayer patiently moving the ball from side to side, Kaufmann alone in their half, striving to win any clearance that came his way.

As Aissa Laïdouni, Alex Kral and Josip Juranović waited to come on for Schäfer, Khedira and Trimmel, Vogt made another good stop, getting in front of Tella’s whipped in cross from the right. But the subs would make a difference.

Král stretched but couldn’t direct a shot on target almost immediately after coming on, as Laïdouni did brilliantly, patiently taking the sting out of Leverkusen’s possession following another piece of Aaronson skill to rob Tella and bring the ball away from danger.

If anything, Union were finding themselves. Laïdouni gestured to the Gegengerade to keep the volume up before he instigated another fine move, beating Wirtz in the middle and switching the play to a Juranović who hit a bending cross that dipped just an inch too high for Kaufmann to get on the end of on the edge of the six-yard-box.

Leverkusen, too, were waiting for their chance though, and it took yet another save from Rönnow to deny Tella as he tried to bend a left-footed shot inside the back post.

Brenden Hollerbach came on for the tireless Aaronson, and immediately found himself in the thick of things, getting onto a long ball, and winning a corner with his cross, but Doekhi could only head over at full stretch while falling backwards.

Meanwhile with every action, every tackle, every break, the stadium grew louder and louder, the Unioner revelling in the struggle their players showed; the fight inherent in the way that Leite knocked the substitute Jeremie Frimpong off the ball having largely annulled all the danger of the man he replaced, Tella, or in the lunge that Laidouni tackled Kossounou with, with just three minutes of normal time to play.

Union were giving everything, and Wirtz was reduced to scuffing a shot into the waiting arms of Rönnow from 25 yards as the assistant referee showed there were still six minutes to play, and as Lukas Hradecky held the ball longer than he needed to following Doekhi’s flick on from Juranović’s towering throw-in. Doekhi was immediately back in action at the other end, launching himself at Frimpong’s shot as the stadium boiled.

There was still time for Rönnow to save brilliantly from Adli, and to dive at the feet of Victor Boniface – a man Union know all too well from his time at Saint Gilles. But the pressure by now was all Union’s. Kossounou conceded a corner off the irrepressible Hollerbach. Rönnow came up. He won a header. The stadium roared again, somehow even louder this time. Union won another.

Ultimately it would count for little, as the Leverkusen players breathed deeply on the final whistle, their unbeaten record still intact. But Union had been superb in the most trying of situations against the team likely to be Champions in record fashion.

They looked hurt as they took their final round, but the roars of the Alte Försterei only confirmed what they had come so close to achieving, but more importantly of the fight they had shown.