As rain drenched north London and one corner of this ground was ignited in green smoke and white firecrackers, the television cameras panned to a young Arsenal supporter. He stood motionless: hood up, mobile phone in hand, mouth wide open. 

It was a portrait of shock and awe and grudging admiration that encapsulated the mood around this place in the moments after Pedro Goncalves collected possession on halfway, looked up, and floated a shot towards the Arsenal goal. We were just beyond the hour mark and, briefly, time stood still while the ball drifted 45 yards and Aaron Ramsdale scrambled towards his own goal. 

Then both goalkeeper and ball crumpled into the net and this tie was alive again. Last week’s first leg, which ended 2-2, had been a slightly bonkers game. But it produced nothing this barmy.

Until then, Mikel Arteta’s side had been on course for the Europa League quarter finals thanks to Granit Xhaka’s first goal since October. That came in the 19th minute and felt like ancient by the time Sporting completed a remarkable victory on penalties.

Gabriel Martinelli was the unfortunate fall-guy. The visitors’ heroic captain, Antonio Adan, saved his spot-kick – Arsenal’s fourth - and several Sporting players thought that was victory secured. 

Arsenal crashed out of the Europa League after losing 5-3 on penalties to Sporting Lisbon at the Emirates on Thursday night

And so add heartbreak at the end of a long and bruising night for Arsenal.

One that started with the return of Gabriel Jesus from injury but ended with at least two other casualties.

William Saliba appeared to hurt his back; Takehiro Tomiyasu looked to have damaged his knee. Gabriel was struggling by the end, too.

Not what Arsenal needed at the start of four pivotal days, which could end with them eight points clear atop the Premier League.

They could have done without extra-time too. Perhaps the only solace? They can now push for the title without any distractions.

In truth, parity was the most Arsenal merited after 90 minutes in which Sporting carried threat until the end. But then, in the additional 30, the visitors went down to 10 men while Arsenal kept banging on the door. Unfortunately, over two legs, neither side showed much desire to shut the door behind them.

It was February 2020 the last time Arsenal supporters piled in here for a European knockout game.

That night, Olympiacos silenced this slice of north London; not long after, the world began to look very different. Those returning Arsenal fans are still adjusting to this new normal. A club transformed over the past three years.

Arteta wants Arsenal to make this a scene of iconic European nights. At least they should have plenty more practice on his watch.

Last night began with a light show and a tie finely poised. It also marked the homecoming of Jesus. Unfortunately, by the time the striker began to dazzle, Arsenal were two men down. Saliba followed Tomiyasu down the tunnel as Arteta’s side celebrated the opening goal. It was scored by Xhaka, who followed in after Martinelli’s effort was saved. The chance, though, was created by Jorginho’s piercing through-ball.

That briefly eased some of the tension but Sporting would not go away.

They had probably shaded a bitty start, with Francisco Trincao curling just wide, and they had chances after falling behind, too.

Just as in Portugal, Arsenal lacked some control. But just like last week, opportunities weren’t a problem.

Jesus showed flashes of his brilliant best, including one mazy run that ended with a sharp one-handed save from Adan.

Alas his return ended after 45 minutes, with Leandro Trossard the third substitute – sorry, impacter – sent on by Arteta. Two minutes later, another Arsenal body hit the floor. This time, it was Gabriel nursing some pain. Fortunately for the home side, the defender ran it off. Unfortunately for Arteta, Sporting would not stay down either.

Still, nothing Ruben Amorim’s side had created begat the strike from Goncalves that sent this tie towards extra time.

Arsenal will wonder how, in the space of a few seconds, they went from controlling possession on halfway to surrendering their lead. The Sporting supporters, who had begun the march towards this ground five hours earlier, didn’t care one jot. It was a goal to make this trip worthwhile. No wonder they sent for the pyrotechnics.

Arteta sensed danger and sent on both Thomas Partey and Bukayo Saka.

Alas, for a while, Sporting had their tails up. Ramsdale watched a header skim the top of his bar. Then, a few minutes later, the goalkeeper watched Edwards’ shot fly into his face.

It was a hefty blow but a vital intervention. As the end of normal time approached, this ground began to leak: supporters had to clear chunks of seats as mini-waterfalls drenched the first few rows.

But the skies soon cleared and so did Arsenal heads. They ought to have won this in extra-time. Trossard saw a shot deflected on to the post. Gabriel saw one header saved and another cleared off the line.

Manuel Ugarte was shown a second yellow card shortly before this went to penalties. Arsenal had never had a shootout here before last night.

Arteta had never won a home European knockout game as manager, either. He still hasn’t. And so that same corner exploded once more.