Ghana midfielder Thomas Partey provided the opening assist as Arsenal secured a first-leg advantage in their Europa League last 16 game against Olympiacos.
Partey found Norwegian attacking midfielder Martin Odergaard inside the half of the Greek club before the Real Madrid loanee fired home from long range.
The 27-year-old was replaced by Dani Ceballos ten minutes after the second half with the Gunners leading 1-0.
Olympiacos leveled three minutes later through Yousef El Arabi, but a late surge by the English giants saw them reclaim the lead to go on and win 3-1.
Brazilian defender Gabriel Magalhães put Arsenal in the lead with ten minutes left before Egyptian star Mohammed El Nenny sealed victory five minutes from time.
Partey has now made 17 appearances in all competitions for Arsenal and has two assists to his credit.
He is yet to net his first ever Arsenal goal.