So this is how it feels to be there when the English turn up, to be over there when we go over there. On a night of confusion, anxiety and some mild outbreaks of violence around the Emirates Stadium, London had a taste of what it feels like to be caught on the hop by thousands of boisterous, tribal, boozed-up football fans in search of a space to call their own for the night.

Alexis Sánchez soothes nerves after Cologne and fans give Arsenal a fright Read more

First the good news. Arsenal’s Europe League match against Cologne did eventually go ahead, delayed to a 9.05pm start after massive congestion problems outside the stadium. Tens of thousands of confused and anxious football supporters mingled on the concrete walkways around the ground without losing their heads or becoming violent or coming close to the kind of problems severe overcrowding can cause. Inside the stadium, where an estimated 20,000 Cologne fans gained entry, the scene was fevered and edgy but largely peaceful as supporters intermingled in the stands. It really could have been so much worse given the numbers involved, and given the state of garrulous all-day intoxication of the Cologne fans who seemed to have spent most of Thursday drinking high-strength Belgian lager in various spots around central London.

In the most fraught moments leading up to kick-off police riot teams could be seen snaking through the huge crowd at the turnstiles, and some arrests were made after a group of Cologne fans tried to storm one of the entrances. There were scuffles among the visiting fans and some nasty moments in the away end in the delay before kick-off as those with tickets in other parts of the ground tried to force their way into the main mass of Cologne fans and fought intermittently with stewards. Eventually the police arrived, hundreds of extra officers having been scrambled to deal with a situation that appeared to have caught them on the hop a little.

Facebook Twitter Pinterest Flares are set off in the away end by Cologne fans. Photograph: Robin Jones/Digital South/SilverHub/Rex/Shutterstock

Throughout the day it had been clear to anybody watching that something unusual was building. Cologne are one of the Bundesliga’s most boisterously supported big-city clubs and their fans have been in a fever at their first European campaign in 25 years. Warnings of a massed ticketless invasion had been circulating ever since the draw. Only this week Arsenal had issued a warning to fans not to travel without tickets. A spike in memberships taken out in Germany had been reported and new German-based ticket applications refused.

Forewarned, then. But not apparently prepared. As north London yawned its way grudgingly through Thursday afternoon’s preliminaries a massed phalanx of the travelling supporters army marched and sang and lit fireworks and thundered its way slowly from Oxford Street to Holloway Road. Perhaps police could have intercepted them further from the ground. Surely they could have been there in larger numbers at the start.

The visitors were largely well behaved, the response of police and club sensible, if a little strained

By six o’clock a surge of German fans appeared to be simply wandering around the stadium, mingling with commuters, blocking out side streets. It felt good natured, if a little claustrophobic. Last week there were roadblocks and police horses in west London to tackle 1500 travelling Millwall fans. Here two hours before kick-off a lone officer could be seen energetically pointing an endless procession of chanting fans away from the wrong side street turning.

As the bridges leading into the ground were closed and news emerged of the delay to kick-off rumours circulated of German fans buying Arsenal scarves in the club shop to gain entry to the home ends. Some said Cologne fans had been allowed to sit in their ticketed seats alongside the home fans, but instructed not to cheer if their team scored – a fanciful piece of rumour–mongering that went out of the window the moment Jhon Córdoba scored a spectacular opener after nine minutes, drawing leaping celebrations all around a genuinely fevered Emirates. Arsenal fans leapt to their feet in turn, urging some stewards to expel the away fans in their midst. Everybody kept their head, just about.

Facebook Twitter Pinterest Cologne fans celebrate their opening goal by spilling over the barriers at the Emirates. Photograph: Craig Mercer - CameraSport/CameraSport via Getty Images

What could Arsenal have done differently? What is the correct protocol for dealing with 20,000 boisterous people turning up in your corner of the city demanding entry? In the past England fans and the English media have been critical of police abroad kettling or herding or even lobbing gas canisters. Here the visitors were largely well behaved, the response of police and club sensible, if a little strained, and with a sense of having been taken by surprise, for all the warnings.

Arsenal match delayed on safety grounds as 20,000 Cologne fans travel Read more

On the balance of danger it was clearly the right decision to play the game rather than abandon it and try to funnel 20,000 noisy Germans down Holloway Road. But there will be consequences. Cologne will perhaps be censured for the broad offence of failing to control their fans, or in effect failing to discourage them from travelling. Arsenal will have to answer for the presence of so many away fans in the wrong parts of the stadium, the causes of which will have to be unravelled properly, never mind the hot takes and rumours. If the sale of 15,000 extra tickets really was the work of touts, there are some seriously hard working duckers-and-divers around north London.

There will also be further murmurs about the wider issues of violence in German football, the Nazi-era songs last week at the international against Czech Republic in Prague, the regular problems at Bundesliga games. Here there were flares in the extended away section. Really though, it was relatively mild by the end, a fraught, confusing night that always felt balanced, just about, on the right side of orderly.

What, as an end note, to make of Arsenal here? There was undoubtedly something gripping about the spectacle of the Emirates being overrun by a more vibrant, angrier, passionately involved footballing culture. Even in the good times Arsenal’s home can feel a little hollow and tinny, an orderly corporate shell. They aren’t alone. Many English grounds must seem bafflingly silent, colourless places to European fans raised on the idea of an English terrace culture. Sorry, chaps, but we sold that off a while back. And please, remember to exit via the gift shop.

On the pitch a second-string team stuck at it, on what could have been a traumatic night. A shift of shape helped bring Sead Kolasinac’s thumped equaliser before goals from Alexis Sánchez and Héctor Bellerín tilted the night in Arsenal’s favour.