Olympiakos got their Champions League campaign off to a winning start as they recorded a 3-2 victory over Atletico Madrid in the Group A clash at Karaiskakis Stadium.
Arthur Masuaku opened the scoring for the hosts and Ibrahim Afellay doubled their lead after 31 minutes before Mario Mandzukic pulled one back for Madrid before half-time.
Konstantinos Mitroglou made it 3-1 midway through the second half before Antoine Griezmann struck for last season's beaten finalists at the end.
Eric Abidal was the first Olympiakos player to test the visiting defence but his long-range thunderbolt from the left sailed past the right post.
It did not take the hosts long to open the scoring and Masuaku struck after 13 minutes to hand the Greek champions the lead.
The 20-year-old collected the ball from Afellay on the left and made no mistake as he drilled it low past Jan Oblak from 25 yards out.
Atletico came close with a chance of their own four minutes later as Gabi's outswiniging corner from the right found the head of Mandzukic, but the Croatia striker sent the ball over the crossbar.
Abidal blocked a close-range header from Mandzukic midway through the first half as the away side fought their way back into the match.
But just after the half-hour mark, the hosts got on the scoresheet for the second time as Alejandro Dominguez picked out Afellay, who powered the ball home from the centre of the 18-yard box to double his side's advantage.
However, seven minutes later Mandzukic got his reward for his numerous first-half missed chances as he collected Cristian Ansaldi's cross and sent home a fantastic close-range header into the bottom corner to make it 2-1.
The second half began at a slower pace than the first finished and it was the visitors that came closest to scoring as summer signing Griezmann tested Roberto Jimenez - but the Olympiakos goalkeeper managed to tip the ball over the bar.
The home side hit back deep into the second half with their third goal as Pajtim Kasami picked out on-loan Greece striker Mitroglou in the box, who made no mistake with his close-range volley.
Atletico were desperate to get back into the game now but Jimenez made a comfortable catch as he denied an Alessio Cerci header with little over 10 minutes left.
The visitors' pressure paid off as Griezmann picked up Jorge Koke's cross from the left and converted from close range - but they could not find an equaliser.