Arsenal put off-field chaos behind them to come from behind and claim victory in their Europa League opener against Cologne.
Crowd trouble outside the Emirates meant kick-off was delayed by an hour with 20,000 German supporters having descended on London.
And when Jhon Cordoba fired the visitors ahead early in the piece, it looked like being a nightmare evening for the hosts.
But Arsene Wenger's side rallied in the second half with Sead Kolasinac levelling shortly after the break.
Alexis Sanchez's stunner made it 2-1, before Hector Bellerin sealed the deal nine minutes from time.
Here are five talking points from the Emirates...
1. Off-field chaos delays kick-off
It was an eventful night before a ball had been kicked in north London.
Around 20,000 Cologne fans arrived in London to support their team, despite the away allocation being just under 3,000.
Stewards and police were forced to hold spectators outside the stadium amid safety fears, before turnstiles were eventually opened with a one-hour delay to kick-off announced.
Thousands of Cologne fans had managed to attain tickets in home sections of the Emirates, with some trying to gain access to the away end from inside the ground.
Four arrests were made, and it's unlikely we've heard the last of it.
2. Wenger wins game with tactical adjustment
Arsene Wenger made plenty of changes with Chelsea in mind and it was evident from the start that the 3-4-3 was not working.
At 0-1, Wenger switched it up to a 4-2-3-1 and it worked: substitute Sead Kolasinac used the ball well in deeper areas and Alexis Sanchez was able to run at Cologne from the left channel.
Will the Gunners boss be brave enough to not match up the Blues on Sunday? Or will he fall into the trap of mimicking Antonio Conte with a system that still may not entirely suit his squad.
3. All is forgiven with Sanchez
It was only a few weeks ago the Chilean was looking to move to Manchester City, with the Citizens launching a Deadline Day bid for the forward.
Arsenal were unable to sign Thomas Lemar as a replacement, meaning the 28-year-old was forced to stay put in north London.
He's since returned for the Gunners, and featured in their 4-0 hammering at the hands of Liverpool in the Premier League. His body language during the game only added to the idea he no longer wants to be at the Emirates.
But against Cologne is seems everything was suddenly forgiven.
Sanchez showed exactly why Arsene Wenger was so keen to keep hold of him with a stunning long-range strike to ensure Arsenal took all three points from the fixture. Football is a fickle game.
4. Kolasinac can become match-winner for Gunners
Whether Wenger was saving Kolasinac for Sunday or not remains to be seen, but the former Schalke star has proven to be decisive in the final third.
His strength also helps the Gunners defend better from set-pieces and his composure on the ball offers a better outlet down the left flank.
The Gunners may look for Kolasinac's quality on the ball as a mainstay of their attack and should he link up with Alexis Sanchez on a regular basis, Wenger may have the luxury of one of the best left sides in the Premier League.
5. Cologne's struggles continue
After three games of the Bundesliga season, Cologne are bottom having lost all three matches, scoring just one goal and shipping seven.
They will have seen the Europa League as a welcome distraction and a chance to turn their season around, and will have been buoyed by the early goal.
But old frailties were exploited by the Gunners after the break, and there would be no joyous return to European competition after 25 years away.
