Bayern Munich 2-0 Barcelona
Bayern maintained their winning start in Group C after beating Barcelona 2-0 at the Allianz Arena.
Robert Lewandowski was twice denied the opener for Barca against his former side by goalkeeper Manuel Neuer, with a flurry of chances from both ends.
However, Lucas Hernandez broke the deadlock for the Bavarians early in the second stanza with a close-range header off Joshua Kimmich's corner.
Leroy Sane doubled their lead six minutes before the hour-mark, taking his tally to three goals in the Champions League this season.
Liverpool 2-1 Ajax Amsterdam
Liverpool finally got their Group A campaign up and running after a last-gasp 2-1 win over Ajax Amsterdam at Anfield.
Mohamed Salah gave the Reds the opener on 17 minutes, but Mohammed Kudus levelled matters for Ajax ten minutes later.
However, the night belonged to the Reds as Joel Matip snatched the winner for Jurgen Klopp's charges in the last minute.
Bayer Leverkusen 2-0 Atletico Madrid
Atletico Madrid's perfect start in Group B came to an end after a late 2-0 loss to Bayer Leverkusen at BayArena.
Atletico had a penalty appeal referred to the Video Assistant Referee (VAR) after a ball hit the arm of Edmond Tapsoba midway through the first stanza but the VAR stood with the on-field decision not to award a spot-kick.
Bayer, however, enjoyed a quick start in the second stanza as Patrik Schick was denied the opener by the crossbar and Adam Hlozek struck the post from the rebound.
Robert Andrich eventually broke the deadlock for the home side six minutes before time and Moussa Diaby buried the game three minutes later.
FC Porto 0-4 Club Brugge
Club Brugge maintained their perfect start in Group B after thrashing FC Porto 4-0 at Estadio do Dragao.
Ferran Jutgla sent Brugge ahead on the first quarter-hour mark from the penalty spot and Kamal Sowah gave them a two-goal cushion two minutes inside the second stanza.
Andreas Skov Olsen put the game to bed for the visitors five minutes later and Antonio Nusa put the icing on cake in the last minute.
Olympique Marseille 0-1 Eintracht Frankfurt
Eintracht Frankfurt registered their first points in Group D after edging Olympique Marseille 1-0 at Stade Velodrome.
Jesper Lindstrom broke the deadlock for Eintracht just before the halftime break and Daichi Kamada had a goal for the visitors in the last ten minutes disallowed by the Video Assistant Referee (VAR) for offside.