Tuesday's highlights
• Headlining the night is a clash between arguably the two best sides in the world, with reigning European champions PSG playing host to an in-form Barcelona
• Before that, Fenerbahce and Borussia Dortmund will get the ball rolling with games against Slavia Prague and Sabah Baku, respectively
• Elsewhere in the late kick-offs, Liverpool will welcome Villarreal to Anfield, Manchester City will play host to AEK Athens, and Atletico Madrid will visit Stuttgart
• It's a big night at the bottom of the table, with FC Porto vs PSV, Roma vs Slovan Bratislava and Napoli vs Bodo/Glimt all featuring sides that badly need to get some points on the board after stuttering starts
Live updates and insights
Tuesday, October 20th
17:42 CET - We're just over an hour away from this evening's two early kick-offs, as Fenerbahce host Slavia Prague in Istanbul and Borussia Dortmund travel to Azerbaijan to face Sabah Baku.
Here are the starting lineups from Baku, with Niko Kovac fielding a strong side as the German giants look to bounce back from a disappointing defeat to Bodo/Glimt on matchday two.
16:15 CET - Hello and welcome to Flashscore's coverage of this week's Champions League action!
All eyes are on Paris tonight, with the French capital playing host to a clash between arguably the two best sides in the world right now, PSG vs Barcelona.
The reigning French and Spanish champions head into their meeting occupying the top spots in the League Phase table, having each won their first two matches in emphatic fashion.
It's been a similar story for Barcelona domestically, with Hansi Flick's side winning all nine of their LaLiga matches this season and scoring 39 goals in the process. Led by the unstoppable duo of Lamine Yamal and Raphinha, they haven't failed to claim victory in a competitive match since May.
They'll face their biggest test of the season tonight, though, because after a slow start to their campaign, Champions League holders PSG have won each of their last six, and were at their glorious best last time out on the European stage, beating Manchester City 4-2 away from home.
That clash will kick off at 21:00 CET, and you can read our preview of it here.
Those two aren't the only giants in action, with Liverpool and Manchester City playing host to Villarreal and AEK Athens, respectively, in the north of England, Atletico Madrid visiting Stuttgart, Napoli welcoming Bodo/Glimt to the Stadio Diego Armando Maradona, and Borussia Dortmund taking on Sabah Baku in an early kick-off.
Perhaps the highest stakes, though, are in the matches involving clubs lower down the table, with FC Porto and PSV both in need of a win in their meeting having made poor starts to their European campaigns, and Roma knowing that anything other than three points against Slovan Bratislava will leave them playing catch-up.
Click here for a look ahead to all of the week's biggest games.