19:50 CET - The team news is in for the first leg, and we have a couple of surprises.
Arsenal's front three of Viktor Gyokeres, Gabriel Martinelli and Noni Madueke is not their strongest, but Eberechi Eze is on the bench after limping off at the weekend, whilst Kai Havertz hasn't made the trip.
For Atletico Madrid, Diego Simeone has opted for Julian Alvarez and Antoine Griezmann up top with Alexander Sorloth in the dugout to start the game.
19:00 CET - Has everyone recovered from yesterday? We witnessed one of the greatest games of football ever played as PSG took a slender advantage into next week's second leg, thanks to that nine-goal thrill ride at the Parc des Princes.
Catch up with the bonkers encounter right here.
Tonight's offering is unlikely to match that level, but intrigue still remains as Mikel Arteta and Diego Simeone face off in a battle of likely pragmatism.
Coming into the game, both sides won at the weekend, with Atleti's focus solely on the Champions League, whilst the Gunners are fighting on two fronts as the Premier League title race is set to go down to the wire.
The two sides met back in October during the League Phase with Arsenal running out 4-0 winners, but that was then, and this is now.
Arteta's men have struggled under pressure in recent weeks, whilst Atletico knocked out Barcelona over two legs in the quarters, meaning this match feels like it will be a lot tighter than the one earlier in the season.