Mikel Arteta's side came into this tie off the back of a dramatic late winner vs Benfica to advance from the round of 32.
With poor form in the Premier League this season, Arsenal have once again had to turn to European competition as their most likely chance of qualifying for next season's UEFA Champions League.
Story of the match:
The Gunners began the tie brightly with fullbacks Kieran Tierney and Hector Bellerin getting in dangerous positions to put balls into the box. Arsenal dominated the early exchanges, Thomas Partey and Granit Xhaka were responsible for distributing the possession into the wide areas.
Chances for Martin Odegaard and Pierre-Emerick Aubameyang weren't taken until the first struck one from all of 30 yards and despite the keepers’ best efforts, the ball thundered into the back of the net.
With the away goal advantage now with the north London club, Arteta’s side sat deeper and attempted to hit their Greek opponents on the counterattack.
The Gunners started the second half on the back foot and were pressured by Olympiacos but after the original flurry of attacks, Arteta’s side regained possession of the ball and moved higher up the pitch through the midfield.
Partey was substituted for Dani Ceballos early on in the second half in a tactical substitution which looked to rest Partey for the north London derby on Sunday.
Ceballos made an immediate impact on the game for all the wrong reasons just minutes into coming on as the Spaniard lost possession deep in his own half from which Olympiacos capitalised upon and equalised past the outstretched glove of Bernd Leno.
Reenergised from their success, Olympiacos attacked Arsenal with pace on the counter which saw the Greek side come close on occasions.
Just as Mikel Arteta was preparing a triple substitution for Arsenal, a short corner routine came off for the Gunners with Gabriel rising highest to power home a terrific header into the side netting.
The Gunners then added to their advantage when Mo Elneny struck home a sweet strike from 30 yards which cannoned in off the post.
Clever substitutions help Gunners see out first leg:
Mikel Arteta introduced energised players to Arsenal’s side in just the right moments for the Gunners to ensure that the victory was earned. Substitute Elneny also came on and scored a fantastic goal to put breathing space between themselves and their Greek opponents.
The triple substitution Arteta made kept the team fresh and ensured they didn’t tire out before the big two games coming up for the Gunners over the next weeks.
Man of the match:
Martin Odegaard was one of Arsenal’s star performers on the night with the 22-year-old Norwegian taking risks and pulling the strings in the middle of the park.
Despite some sloppy moments and lapses in concentration, The Real Madrid loanee was one of the only Arsenal players who looked prepared to try high risk passes, runs and shots.
One of these key moments took place when he struck the ball into the net from outside the box to put his side 0-1 up. Odegaard’s slick passing and silkiness on the ball made him stand out from the rest of his teammates.
The Norwegian now leaves the Arsenal hierarchy with a headache as to whether the Gunners sign him permanently or extend his loan next season.
Arsenal have two season defining games ahead as they face Tottenham and a second leg against Olympiacos.
Although Mikel Arteta’s side don’t look likely to qualify for next seasons Champion’s league via the Premier League, bragging rights against their fierce rivals Spurs demand full commitment and fight with everything to play for.
Sunday’s game is a must win for Arsenal if the Gunners have any hopes of finishing in the top six.