LONDON — In the 51st minute, as Atletico Madrid looped a ball into the space between backline and goalkeeper, came Arsenal in microcosm. Well, almost. Mikel Arteta’s side are not accustomed to the sort of calamitous error that William Saliba appeared to have made when his header sat up invitingly for Giuliano Simeone to poke away from David Raya.

Against 95 other teams in Europe’s top five leagues, this was already a goal. The goaliest goal that ever did goal. There are probably a few who would have afforded Simeone a chance to pull up a pew, go through his correspondence, pick out a recipe for dinner tomorrow and then have a think about whether he should put the ball in the net later. Here’s looking at you, Metz. 

What they don’t have, what no other team has is a defense anchored by Gabriel Magalhaes. The big Brazilian, Saliba, Raya, some chunky fullbacks: that’s a blueprint that’s just as capable of carrying a side to the Champions League final as the attacking firepower on the other side of the bracket. That is how they find a way to keep a clean sheet when the goal is gaping in front of Atleti.

It might have been gambling with a penalty but what choice did Gabriel have but to put his potential involvement in the Champions League final on the line? Get this wrong and it’s a red card, a 79% chance of an equalizer and an agonizing 40 minutes or more for the hosts. It’s a strange one. Gabriel doesn’t clearly and indisputably touch Simeone. He certainly doesn’t touch the ball either. He makes his presence felt, though, and perhaps that is enough to force a spooning shot to nowhere in particular. Daniel Siebert evidently felt Gabriel had got it right. His VAR team agreed. Even Diego Simeone refused to be drawn into questions about the officiating favoring Arsenal.

There will be those who think that he did not quite judge his challenge right, that Gabriel got a bit of Simeone or not enough of the ball. Here’s the thing, though. You have done something quite spectacular if you turn that situation into: a debate about a penalty, a debate about whether there was really a shot in the mix (at the time of writing, there was and it was worth 0.22 xG) and nary a corner to defend.

That has been Arsenal right the way through this competition. Six goals conceded in 14 games, only two of them in the knockout stages. There are vanishingly few teams who can better that record: Chelsea in 2020-21, the Gunners themselves got to their only previous final 20 years ago off the back of a defense that allowed just two goals. Both those teams seemed to bottle lightning. Thomas Tuchel’s side kept it up for a while longer but never quite hit the lockdown levels that took them past the Madrids and Manchester City. Arsene Wenger’s was some strange convalescence of science and magic, Emmanuel Eboue and Mathieu Flamini somehow the full back pairing of a European Cup finalist.

This, Arsenal, they’ve been at this for years. And everyone has been at it. You don’t last long in Arteta’s XI if you can’t be trusted out of possession. Just ask Eberechi Eze. On this night, everyone was bought in, starting at the top of the pitch, where Viktor Gyokeres scrapped for every ball. 

“It’s immense,” said Arteta of his rearguard. “You talk about Gyokeres and he’s the first one to set the tone, the rhythm, and the habits that he shows when we don’t have it [the ball] and that’s a team effort.”

What they delivered was only a heightened version of their norm. Antoine Griezmann, Ademola Lookman, whatever version of Julian Alvarez Diego Simeone was able to roll out: all limited to barely half an expected goal. Fifteen minutes or more might pass without Atletico Madrid getting a touch in the penalty area. You sensed that this was a performance that Diego Simeone, whose great sides punched above their weight off the back of sensational defending, could get behind.

There would be no drawing him on the penalties that might have been — a foul on  Griezmann had also caught the eye of the travelling Atletico contingent — nor the way that Arsenal used the clock to their advantage late on. You didn’t have to be a native Spanish speaker to pick up the admiration emanating from the defeated manager. 

“If we got knocked out, it’s because our opponents deserved to go through,” he said. “They took their big chance in the first half; they deserved to get through. I feel calm. I feel peaceful. The team gave absolutely everything.”

No such emotions at the Emirates Stadium. How could there be after the finest hour this ground has so far? 

“I don’t think you can underestimate what we have done in this competition up to this point,” said Declan Rice. “I think we have every right to celebrate that moment. The most prestigious competition in club football. We are just trying to soak it all in.”

Up next, the greatest test of the greatest defense of this generation. Whether it’s Khvicha Kvaratskhelia and Ousmane Dembele or Harry Kane and Michael Olise — plus plenty in the supporting cast for both sides — this is going to be an almighty test for Arsenal. One they have negotiated before but not with the stakes as high as they will be in Budapest.

It can be done. That much was clear Tuesday night. Even when it looks like there is nothing Arsenal can do to stop the other team scoring, they find a way.