Aaron Ramsey can do no wrong. Everything he touches turns to goals right now and, if his 11th of an already stellar season was arguably the scruffiest of the bunch, it positively dripped with prestige value.
Arsenal had set up to contain Borussia Dortmund, the beaten finalists in the Champions League last time out and one of Europe's most fancied teams. For long spells Arsène Wenger's players relied on defiance, which was epitomised by Per Mertesacker, who rose to the challenge on every level in his native Germany. Yet when they ventured forward for the first time ofany note, Ramsey threw himself in where it hurts to bring Dortmund to their knees.
The goal followed the cheap surrender of possession by the home side but Arsenal punished them with the same ruthlessness that Dortmund had shown in their own smash-and-grab victory at the Emirates Stadium two weeks previously. Jürgen Klopp, the Dortmund manager, and the pulsating Westfalenstadion fell silent. This was a case of Klopps and Robbers Part II.
Tomas Rosicky, the former Dortmund midfielder, switched the play to the right and, when the otherwise quiet Mesut Özil floated over a cross, Olivier Giroud challenged with every ounce of his physical strength. He did what he had to do and, suddenly, there was Ramsey, stretching to get there first, ignoring Neven Subotic's raised boot, to head beyond the clutches of Roman Weidenfeller. Ramsey has now equalled his goals return from his previous five seasons at the club.
One-nil to the Arsenal has not sounded this good for some time. There had looked to be only one likely winner, as Dortmund pushed and created what chances there were in this high-stakes collision. But Arsenal are increasingly suggesting that theirs can be a different story this season and here was the most persuasive evidence yet. Their unbeaten run away from home spans eight months and 15 matches. They were brave and, ultimately, decisive. They can almost touch the last 16 of this competition.
It was a night when Arsenal's concentration could not and did not waver. Dortmund hunt in hi-viz packs, probing for any sign of weakness but the visitors held their shape, tracked their men and got feet in. There were nervous moments, yet Arsenal toughed it out through the sheer force of their will.
The first half was stifling but Dortmund carried the threat, with the big chance being created for Henrikh Mkhitaryan eight minutes before half-time. Robert Lewandowski, under pressure from Laurent Koscielny, and Jakub Blaszczykowski combined to send him through but, confronted by Wojciech Szczesny, he curled his shot wide of the far post. It was a moment of expensive wastefulness.
Subotic had earlier nudged narrowly wide of a post following a Marco Reus set piece; Blaszczykowski did not get hold of an effort after slick Dortmund build-up while Mertesacker stepped out to time a challenge on the onrushing Reus. Mertesacker, saluted in song as the largest of Germans, set the tone for Arsenal with a succession of important interventions while Koscielny also put his body on the line. They were in no mood to allow anything or anyone to pass.
Tempers frayed. Mikel Arteta grabbed Blaszczykowski's shirt and he was booked while the dangerous Reus tugged back Rosicky and was not booked, which surprised everybody. Arteta, the Arsenal captain, flirted with a second card, losing his cool after being penalised for one foul on Lewandowski and a part of the battle seemed to be located between the ears as the intensity pounded. There were ironic cheers from the away support when the referee, Björn Kuipers, booked Lewandowski after a clash with Ramsey.
Arsenal appeared content to dig in, to use their possession to draw the sting from Dortmund rather than commit too hard going forward. As the fine rain tumbled down and the chill bit, Klopp's team squeezed higher at the start of thesecond half, ratcheting up the pressure. The full-backs sought to overlap. Reus, completely unmarked, drew a save from Szczesny with a header whereas Mkhitaryan fed Blaszczykowski and his low shot was repelled by the goalkeeper. Reus put the rebound into the net but he was flagged for offside.
Yet Arsenal turned the tie on its head in dramatic fashion when they forged ahead to wild scenes among the travelling fans. It was a moment that will live long in their memories and, rather abruptly, their team crackled into life in the final third.
After Reus had swung and missed in front of their goal, Ramsey took Giroud's cross down and forced Weidenfeller into a smart save. From a Santi Cazorla corner, Giroud saw a shot scrambled off the line while Mertesacker went agonisingly close on two occasions, the second a looping header on to the top of the net.
Dortmund pushed but they had nothing left. For Arsenal this was the grandest of statements.