Arsenal now have a run of positive results to match the feel-good factor around the Emirates Stadium after stringing together three successive victories.
Mikel Arteta has not taken long to transform the Gunners' fortunes and they are now gearing up for a defining period in their campaign.
Premier League wins over Newcastle United and Everton either side of the victory in Greek capital has lifted Arsenal into ninth place, four points adrift of fifth - potentially enough for a Champions League spot.
The North London outfit also have a favourable last-16 tie at Portsmouth in the FA Cup next week, but Arteta will not for one second let his players take their eyes off the ball.
Having done the hard work at the Karaiskakis Stadium, it is now a case of seeing the job through on home soil on Thursday against the best side Greece has to offer.
Olympiacos returned to winning ways with a 1-0 win at second-place PAOK at the weekend to further stretch their lead at the summit, making it four victories in their last five either side of the Arsenal loss.
Overturning the one-goal deficit will not be easy for Pedro Martins' side given that they have lost 10 of their last 11 away games in European competition, not including qualifiers.
Furthermore, they have won just two of their 32 European ties when losing the first leg, while Arsenal have progressed from all 17 such ties when winning the first leg away from home.
Arsenal's Europa League form: WWDLDW
Arsenal's form (all competitions): DWDWWW
Olympiacos's Europa League form: L
Olympiacos's form (all competitions): DWWWLW
Sead Kolasinac picked up a shoulder injury early on against Everton to cut short his first start in six matches.
Lacazette was named among the subs against Everton, despite scoring in back-to-back games, but that should mean he is fit to start against Olympiacos.
As for the visitors, Ruben Semedo picked up another yellow card in the reverse fixture and will therefore serve an automatic one-match ban.
Hillal Soudani is Olympiacos's only other absentee after being ruled out with a long-term knee injury.
Arsenal possible starting lineup:
Leno; Sokratis, Mustafi, Luiz, Kolasinac; Guendouzi, Torreira; Nelson, Willock, Martinelli; Lacazette
Olympiacos possible starting lineup:
Sa; Elabdellaoui, Cisse, Ba, Tsimikas; Fortounis, Guilherme, Camara; Masouras, El-Arabi, Valbuena
We say: Arsenal 2-0 Olympiacos (3-0 on aggregate)
Lacazette's late away goal in a largely forgettable first leg ensures Arsenal have one one foot in the last 16. The Gunners have been in good form of late and will look to keep that momentum going with a routine home win on Thursday to get themselves over the line.