Arsenal's Europa League tie with FC Koln on Thursday night descended into chaos before it ever began.
The game was delayed by an hour as police struggled to deal with the 20,000 strong Koln fans that made the trip from Germany and proceeded to take over London.
Videos have captured the visitors taking on police outside of the ground and stewards once they managed to get inside the stadium and while there was a great atmosphere come kickoff, the scenes before the game spoiled the occasion.
Koln would go on to take an early lead too through Jhon Cordoba, a lead which only ignited the now split fan base further.
Arsenal scored three second half goals to secure a 3-1 victory and restore order on home soil, but Koln's overwhelming presence in the Emirates Stadium truly made it a game to remember.
But, how did they get in?
One video shows the fans trying to force their way in from the outside against heavy police resistance.
However, as reported by The Sun, one Twitter user claims Arsenal fans were selling their tickets - worth around £35 - for as much as £1,000 to Koln fans.
Of course, Koln fans were desperate to see their side play at the Emirates and the notion itself is believable, could around 17,000 really have paid that much?
Although the club had an allocation of 2,900 for the away end, according to Goal, 4,500 of Koln fans were inside the ground at kick off.
That's still a hefty increase and other reports have suggested that Koln fans were buying Arsenal home shirts in order to purchase home tickets at the ticket office.
Goals from Sead Kolisinac, Alexis Sanchez and Hector Bellerin ensured Arsenal had the last laugh on the night and the Gunners kicked off their first dabble in Europe's secondary competition since losing the 2000 final with a win.
Arsenal are set to launch a full review into the incident and they will hope to avoid similar circumstances when their eastern European counterparts Bate Borisov and Crvena Zvezda come to town as Group H rolls on.
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