Holders Real Madrid chased away some of their early-season blues when Gareth Bale scored the pick of the goals in a 5 1 rout of FC Basel in their Champions League Group B opener.
After a deflected Nacho effort put Real 1-0 ahead in the 14th minute, Bale raced on to a Luka Modric pass and dinked the ball brilliantly over onrushing Basel goal-keeper before volleying into an empty net.
A minute later, Bale found space on the right of the penalty area and sent over a low cross for Cristiano Ronaldo, last season's Champions League top scorer with 17 goals, to tap in at the far post.
James Rodriguez made it 4-0 before Derlis Gonzalez almost immediately pulled a goal back for the visitors.
Karim Benzema completed the scoring in the 79th minute as Real became the first club to score 1,000 goals in European competition.
Elsewhere, Mario Balotelli scored his first goal for Liverpool and captain Steven Gerrard scored a penalty as the home side got their campaign up and running with a 2-1 win over Ludogorets.
Last season's beaten finalists Atletico Madrid, however, were shocked at 3-2 at home by Olympiakos.
Atletico had remained unbeaten at home all throughout last season's campaign.
Borussia Dortmund comfortably beat Arsenal 2-0 with a dominant performance that saw them overwhelm their error prone opponents.
The win puts Dortmund in the driving seat in Group D on three points with Galatasaray and Anderlecht drawing 1-1 in Turkey in the other game in the section.
Olympiakos 3 - 2 Atletico Madrid
Juventus 2 - 0 Malmo
Liverpool 2 - 1 Ludogorets
Real Madrid 5 - 1 Basel
Monaco 1 - 0 Bayer Leverkusen
Benfica 0 - 2 Zenit St Petersburg
Galatasaray 1 - 1 Anderlecht
Borussia Dortmund 2 - 0 Arsenal