Red Star 5-2 Barcelona
Barcelona put on an impressive showing to secure a 5-2 victory over Red Star Belgrade on Wednesday night.
The Catalan giants broke the deadlock after 13 minutes when Raphinha's inviting free-kick found Inigo Martinez, who guided a header into the far corner.
The hosts showed no signs of backing down as they restored parity in the 27th minute via the boot of Congo international Silas.
Barcelona were able to restore their lead just before the break when Robert Lewandowski showed good reaction to slot home the rebound after Pedri shot had hit the upright.
Hansi Flick's side carried that momentum into the second half, with Lewandowski completing his brace while Raphinha and Fermin Lopez completed the rout.
Milson grabbed a second goal for the home side.
Inter Milan 1-0 Arsenal
Arsenal suffered their first defeat in the League Phase after losing 1-0 to Inter Milan at the San Siro.
Martin Odegaard was back in the Gunners squad but only started on the bench as Ben White came in as the only change from the loss to Newcastle United over the weekend.
Inter got a lifeline on the stroke of halftime after being awarded a penalty, which Hakan Calhanoglu converted to give his side the lead.
Paris Saint-Germain 2-1 Atletico Madrid
Atletico Madrid rallied from behind to secure a 2-1 victory over Paris Saint-Germain in Paris on Wednesday night.
The home side opened the scoring after 14 minutes when Ousmane Dembele won possession high up and played in Warren Zaïre-Emery, who calmly slotted home.
Atletico weren't behind for too long as Nahuel Molina slammed home from close range after the ball ricocheted into his path.
With the game seemingly headed for a draw, Angel Correa popped up with the winning goal for Los Rojiblancos in the third minute of stoppage time.
Bayern Munich 1-0 Benfica
Bayern Munich got back to winning ways in the League Phase after defeating Benfica 1-0 at the Bay Arena.
Jamal Musiala got the all important goal in the second half by nodding home from six-yards out after getting on the end of Harry Kane's knockdown.
The victory takes Bayern up to 17th position on the League Phase table.
Club Brugge 1-0 Aston Villa
Aston Villa suffered their first defeat of the campaign after going down 1-0 to Club Brugge.
Hans Vanaken got the game's only goal for the Belgian giants after converting a penalty in the 62nd minute.
Other results:
Shakhtar Donetsk 2-1 Young Boys
Feyenoord 1-3 Salzburg
Sparta Prague 1-2 Brest
Stuttgart 0-2 Atalanta