Olympiacos hosted Marseille in their UEFA Champions League opener somewhat under-prepared having yet to begin their own domestic campaign.
They claimed their 38th Greek title last term but have yet to be start the defence of their crown after games against Kavala and Olympiacos Volou were cancelled; both opponents have been relegated to the fourth-tier of Greek football for match-fixing offences.
So it was little surprise the French side were able to put their poor domestic form behind them to ease to a 1-0 victory.
Olympiacos set up in a 4-5-1 formation that became a fluid 4-3-3 when in possession. Striker Kevin Mirallas was at the apex of their attack and led the line well with his intelligent movement and eye for goal.
David Fuster played in the hole and tried to link the play, supported from either flank by Djamel Abdoun on the right and Franciso Yeste on the left. Away from home they could be dangerous on the counter.
Olympiacos, though, were evidently rusty and will need some games before they find their best form.
Ernesto Valverde is in his second spell at Olympiacos having led them to the double in 2008/09.
He subsequently left to coach Villarreal but lasted just six months in that post before he was sacked.
But in Greece he appears to have a magical touch. He rejoined the club on a two-year contract last August and helped them to claim their 38th league title.
Having failed to reach the quarter-finals in over 10 years, that will be his new challenge at Olympiacos.
The fluidity of the Olympiacos front players is undoubtedly one of their main attributes.
Abdoun in particular has the freedom and intelligence to come from his flank, and join the attack or move freely across the front line.
Mirallas is also a real handful and is someone that will have to be watched by the Arsenal rearguard. He was the top goalscorer in Greece last year and showed enough to suggest when fully fit and up to speed, he will be a danger.
From virtually the first minute, the Greek champions showed a worrying vulnerability from crosses.
Marseille had at least three opportunities from balls into the area that they should have done better with. Runs into the area were not fully tracked and the Greeks' static defending led to opportunites aplenty for the French side.
Olof Mellberg: The Sweden international may be advancing in years but it is that vital experience that is used to hold together the Olympiacos rearguard. While his pace has diminished, his reading of the game remains fully intact. He snuffs out danger before it fully blooms and often covers for team-mates whose bad positioning has caused them to be exposed.
Kevin Mirallas: Arsenal's porous defence could find this striker a problem. Striker's thrive on sharpness and after a few more games, his lithe movement will only improve as will his eye for goal.
Arsenal should have enough to claim six points from their two encounters with Greek opposition. Olympiacos are a side that do have quality but it would be a shock if the Gunners' failed to show their superiority over the two games.