An hour before kick-off, it was already loud. Bowel-looseningly loud. If you’ve been to Wembley you’ll know what sort of volume a stadium is capable of, but compared to the St Petersburg Stadium during Morocco v Iran, the English national stadium was the equivalent of a teenager playing Spotify from his phone on the top deck of a bus.

The new St Petersburg stadium must be up there among the most scenic in the world. On one side a lush park intersected by a tree-lined boulevard, on the other the Baltic Sea, which on a warm day in June is much prettier than it sounds. The elevated motorway sweeping around the side spoils things a touch, but Russia certainly picked a good spot for this ground.

But while outside it might have the air of a delightful picnic, once you got inside it was more like being shut in a room full of Marshall amps and blasted with techno for an hour and a half. Partly that was the soundsystem, partly it was two sets of extremely excited fans trying to outdo each other, but partly it was an old and not especially welcome friend returning to join the fun.

You could hear them as the fans approached the arena, the honking buzz - or the buzzing honk - of those horns, a sound we all thought we’d left in 2010. They might not have actually been vuvuzelas, but the effect was pretty much the same: the sensation that an armoured bee had settled inside your ear and wasn’t minded to move for the whole game.

It made for a pretty extraordinary sensory experience, sometimes exhilarating and sometimes…well, sometimes just a bit much. But it was all borne from joy, from excitement: in the city centre earlier both sets of fans jumped around and sang together, the sort of communal bonhomie you’d expect from a FIFA promotional film, but happening right in front of you and with an irritating journalist filming it on his phone.

All of which was tremendously reassuring. We’ve been told plenty of times that the World Cup is no longer the pinnacle of the game, and of course in terms of the actual quality of play it isn’t. But this is to confuse quality with enjoyment, to think that football can only mean something if it’s of high quality.

Which of course is nonsense. This was, in the second-half at least, a stodgy affair, Iran’s gameplan of frustrating the wildly talented Moroccans paying off beautifully. But when the crushingly unlucky Aziz Bouhaddouz headed into his own goal five minutes into injury-time, the noise doubled, joy and despair screamed from either end of the stadium. This is what the World Cup still means to people, and it’s brilliant.

“We want to dedicate this win, after so many sacrifices, to the real fans of the national team,” said Carlos Queiroz afterwards. “And exclude the ones who jeopardise the preparations of the team. The ones who really support the team and not the ones who pretend they support the team.”

And it now means that Iran - who for obvious reasons do not play football under ideal circumstances, and whose preparations have been significantly disrupted - go into the second round of games ahead of their opponents Spain. Four points can be enough to go through in these World Cup groups, and they’re already three-quarters of the way there.

Queiroz was asked about a pre-tournament comment in which he had likened this to Iran’s own World Cup final: if that was so, then what will their fixture against the Spanish on Wednesday be? “If the game against Morocco was the World Cup final, the game against Spain was the ‘universe’ World Cup final.” The Portuguese could hardly pass up an opportunity to needle, noting: “This is not just Spain - they bring Brazilian players to play with them, changing nationalities.”

It would take the most committed nihilist not to have found this game life-affirming. Astoundingly loud, gloriously heart-warming and tragically unfortunate. That’s football. That’s the World Cup.