Lionel Messi's full debut for PSG ended in a tame 1-1 draw with Club Brugge, while Ander Herrera proving to be shining light
Joao Felix, Antoine Griezmann and Luis Suarez disappointed as Atletico Madrid stumbled to a goalless draw against FC Porto.
Manchester City have made an early claim to top Group A in the UEFA Champions League with a dominant performance against RB Leipzig.
Leicester City will be aiming to kick off their UEFA Europa League campaign with a win when they take on Serie A giants Napoli on Thursday night.
After a difficult weekend in their respective domestic leagues, Rennes and Tottenham kickstart their UEFA Europa Conference League campaigns.
Jordan Henderson and Franck Kessie were among those who impressed as Liverpool eked out a 3-2 win over AC Milan at Anfield on Wednesday.
Erling Haaland scored his 21st Champions League goal as Borussia Dortmund beat Besiktas 2-1 on Wednesday.
West Ham United will hope to begin their UEFA Europa League campaign on a strong note when they face Dinamo Zagreb at Stadion Maksimir on Thursday.
Joe Gomez and Divock Origi make their first starts of the season as Liverpool prepare to take on AC Milan in the UEFA Champions League group stage tie.
Romelu Lukaku scored the only goal of the game while Antonio Rudiger impressed as Chelsea beat Zenit St Petersburg 1-0 in the UEFA Champions League.