Here we were thinking Diego Simeone might have his Atletico Madrid side pull the shutters down in front of their goal, as if closed for business.
That we could see a game dominated by defending in their snarling desire to deny Barcelona any way back into this tie.
Instead, we witnessed an evening of pure entertainment, of mistakes and of brilliance – a proper Champions League scrap in which Arsenal learned their prize for overcoming Sporting CP would be Simeone’s Atletico in the semi-finals rather than Hansi Flick’s Barcelona.
If it is Arsenal who go through, they may be buoyed by what they learned here.
Atletico were their own worst enemies for the first 24 minutes. Twice they conceded clumsily, both after giving away the ball in dangerous areas as Barca dreamed of their comeback, or ‘remontada’ as they say in Spain.
It was 2-2 on aggregate, and the momentum was with Lamine Yamal and company.
Then Ademola Lookman scored what proved to be Atletico’s winner after a single ball in behind Barca’s high defensive line, which, as Flick learned over these two legs, can giveth but also taketh.
They had Pau Cabarsi dismissed in last week’s first leg for a last-man foul to deny an obvious goalscoring opportunity, and the same happened again here, with Eric Garcia red carded for copying his team-mate.
Amid it all, we had Simeone, of all people, telling the Atletico crowd to calm down. As if he had this in control all along, despite this being some script which was written in Madrid.
That even included what happened the day before this clash.
While Barca were training at the Metropolitano Stadium on Monday, Flick was spied discussing the condition of the playing surface with a UEFA delegate. If he believed it was too long, the length was officially deemed to be within the 30mm limit for Champions League matches when checked.
In fact, he was told it measured 26mm, and would be well watered.
Ademola Lookman celebrates his goal which sent Atletico through to the last four
We have seen how away sides can struggle to cope with the Atletico pitch – just look at what happened to Tottenham Hotspur when they slipped their way to a European exit here – and Yamal nearly lost his footing within 30 seconds.
The 18-year-old overcame that wobble as he stayed on his feet, flew forward, and forced Juan Musso into a fine early save.
It was in the fourth minute when the carnage commenced. Clement Lenglet had the ball. He could and should have looked long.
Instead the defender turned, tried to go home to his goalkeeper and was robbed by Yamal, who handed Barca their lead.
It made him the youngest to ever secure 10 goal involvements in the Champions League in a single season, beating Erling Haaland.
After 23 minutes, Atletico gave the ball away again, and Barca scored again, this time through the striker keeping Robert Lewandowski out of Flick’s team in Ferran Torres.
Fermin Lopez was left with blood pouring from his nose after this nasty collision
Just like that, Atletico’s lead had disappeared, and Barca should have scored again via Fermin Lopez’s diving header.
It was saved by Musso, and Lopez was left with blood pouring from his nose after an accidental whack, which forced a lengthy pause in play.
That break helped Atletico, who, after taking a breather, regained the lead in the tie when Atletico broke behind Barca’s high line and Marcos Llorente’s ball into the box found Lookman.
Barca hoped for a penalty before half-time when Dani Olmo was sandwiched in the box. Flick was already aggrieved after his side were denied a spot-kick in last week’s first leg for Marc Pubill’s handball.
So aggrieved that his club logged an official complaint with UEFA.
Flick might be tempted to liken our referee, Clement Turpin, to Dick Turpin now. Barca did not get their penalty despite VAR taking a long look at Olmo dropping down.
After 54 minutes, Barca thought it was 3-3 through yet another fine finish from Torres, only for VAR to rightly call it offside.
It worsened for Flick when Garcia was shown a straight red, again via VAR, for tripping Alexander Sorloth when the striker was through.
And so, after all that Champions League chaos, Atletico await either Arsenal or Sporting.
