Walking down London Road more than an hour before Celtic and Lazio kicked off under the lights at Parkhead there was the sense that it was a big occasion.
Every fan seemed to be moving that little bit quicker as if someone had accidentally sat on the remote and hit fast forward. Motorists turned into driving experts, calculating angles, weighing up distances, manoeuvring into spaces you would normally leave alone; between trees, on pavements or corners. Any other day it would suggest the car had been abandoned.
The Green Brigade, dressed in their distinguishable green, banners and drum in tow, moved in unison towards the luminous stadium, towering incongruously over the nearby buildings, as if an otherworldly craft had chosen the East End of Glasgow as the place in which to decamp.
Turning left, a battalion of police officers and their protected vans lined the street across from a packed Turnstiles Bar with prescient music setting the scene for a night of celebration.
A couple of young supporters were in the back of the police vans, while outside officers huddled around as one told of a scuffle between the two sets of supporters by a burger van. Their voices and the music were soon drowned out by the barking of police dogs, demanding they be freed from their captivity and allowed to roam the streets, sweeping up the atmosphere for themselves.
It's these sights and sounds, before even setting foot into the ground, which makes football such a joyously addictive spectacle. Friends and families discussing, analysing and predicting what is about to unfold, some breaking into song, others just trying to make sure they get one foot in front of another having plied themselves with whatever is their tipple, or whatever they can get their hands on.
It is even more stimulating for evening matches; under the street lights, under the floodlights. The placid nature of a weekend fixture is swapped for a buzz, like beasties transfixed by light.
It was at stark contrast odds to the Lazio fans. Or more accurately the club's ultras.
Fascist figures festooned in black; faces covered, arms raised out in front, in the middle of the day, advancing through the centre of Glasgow. Cretinous creatures, revealing their ideology of hate so brazenly out in the open. If leaders of countries can do similar, as well as lie and obfuscate, then why can't they.
The club had previously pleaded with the support to not give fascist salutes having been punished with a partial stadium closure for the upcoming game with Celtic in Rome after incidents at the Europa League clash with Rennes.
Lazio security manager, Nicolo D'Angelo, said: "Unfortunately, we still have a minority of fans who believe it's acceptable to give the Roman Salute and to make racist comments.
"This is unacceptable and no longer tolerable. We want there to be a healthy relationship with the fans, not this relationship, which has been spoiled for so many years."
It was clearly ignored.
Police were out in numbers to prevent violence in the city and around the ground.
As the match got underway in front of a capacity crowd at Parkhead, all the action was on the pitch as Celtic boss Neil Lennon hoped. There was little to no tension among the two sets of supporters in the ground.
Then not long after the 20th minute, fans in the corner of the Lisbon Lions stand, in the area of the Green Brigade, unfurled a banner which summed up the views of not just Celtic fans but football supporters around the world.
Some scribblers tried to circumnavigate the treacherous connectivity problems which are a staple of the Celtic Park press box to translate the message, as some may have done in the home ends.
Yet, their answer swiftly followed.
'F**k off Lazio' was the chant. It grew louder and louder, reverberating around the ground. The message was clear as it was simple: anti-Lazio, anti-fascism, anti-hate.
In one slice of the cavernous Celtic Park cake, 1300 or so travelling fans were angered, some of whom would have been among the hordes traipsing through Glasgow who were filmed doing the Roman Salute.
The banner was one of many aimed against the right-wing among the Lazio support.
Already there has been talk of the meaning behind certain banners and of Uefa charges.
"All associations and clubs are liable for the following inappropriate behaviour on the part of their supporters and may be subject to disciplinary measures and directives even if they can prove the absence of any negligence in relation to the organisation of the match," as per article 16, section 2 of the UEFA Disciplinary Regulations 2019 states.
Which includes "the use of gestures, words, objects or any other means to transmit a provocative message that is not fit for a sports event, particularly provocative messages that are of a political, ideological, religious or offensive nature."
Certain sections of the Celtic support have had their run ins and disagreements with some decisions taken by the club, whether it is relating to ticket prices or pyrotechnics.
Only on Saturday, in the 6-0 win over Ross County, fans had arranged a protest against their own club over the price of away tickets, having done so on their travels at Hamilton and Hibs - a noble cause.
With regards to the anti-fascist banners on Thursday night it will be interesting how the club take any prospective charge.
But the simple 'Lazio vaffanculo' banner is one which wasn't just a message to fans of the Italian teams, but an obvious one to fans of every club, including their own. Racism and fascism is not acceptable.
It was a message the players helped to deliver on the night, Christopher Jullien heading in a late winner provoking one last rousing chant of 'f**k off Lazio'.