Real Madrid thrashed Swiss side Basel 5-1 as they began their defence of their Champions League title.
After a Marek Suchy own goal had put Real ahead, Gareth Bale, Cristiano Ronaldo, James Rodriguez and Karim Benzema added four more. Derlis Gonzalez scored for Basel.
Atlético Madrid began their campaign with a 3-2 defeat at the hands of Olympiakos. The hosts took the lead through Arthur Masuaku and Ibrahim Afellay drove in a second midway through the first half.
Mario Mandzukic headed in for Atletico to halve the deficit, but Mitroglou restored Olympiakos’s two-goal advantage. Antoine Griezmann scored late on for Atletico.