Atletico Madrid suffered a 3-2 defeat against Olympiakos in Athens to start their Champions League campaign with a whimper.
Arthur Masuaku and Ibrahim Afellay – on loan from Barcelona – gave the Greeks a two-goal lead but a Mandzukic header kept the Spanish champions in the game at half time.
Kostas Mitroglou netted a third for Michel’s side mid-way through the second half, despite a number of chances for the visitors and the introduction of Antoine Griezmann and Alessio Cerci.
Griezmann scored a late second to give Atleti hope but the equaliser never arrived.
Atletico started with Jan Oblak in goal in place of Miguel Angel Moya, one of four changes from the weekend’s derby win over Real Madrid.
Mario Suarez, Cristian Ansaldi and Arda Turan came into the side for Tiago Mendes, Guilherme Siqueira and Raul Jimenez.
Diego Simeone was banned from the touchline after incidents in last season’s Champions League final defeat, with Mono Burgos filling in.
Atletico’s night was compounded by a victory for Juventus over Malmo, the Italians’ 2-0 win leaving Los Rojiblancos bottom of Group A.
Olympiakos 3-2 Atletico
Masuaku 12, Afellay 30, Mitroglou 75 (O), Mandzukic 37, Griezmann 88 (AM)
Olympiakos: Roberto; Elabdellaoui, Abidal, Botia, Masuaku; Maniatis, Kasami; Domiguez, Milivojevic, Afellay; Mitroglou
Atletico Madrid: Oblak; Juanfran, Miranda, Godin, Ansaldi; Arda, Koke, Gabi (Griezmann 58), Mario (Saul 77); Raul Garcia (Cerci 68), Mandzukic
Referee: Pedro Proenca (POR)