Martin Odegaard struck his first goal for Arsenal as the Gunners produced a stunning late show to claim a deserved 3-1 victory at Olympiacos in the first leg of their Europa League Last 16 tie.
The 22-year-old Norway star thundered home a 25-yard drive on 34 minutes with home stopper, Jose Sa at fault after seemingly being beaten by the power.
Ødegaard had earlier missed a gilt-edged opening while Pierre-Emerick Aubameyang saw a deflected header tipped on to the bar as the Gunners dominated.
Olympiacos struggled to create much of note until Arsenal presented them with opportunities. David Luiz was fortunate to get away with a casual clearance towards the end of the first period when Georgios Masouras contrived to fire off target. The visitors did not heed the warning though and were pegged back just prior to the hour when Youssef El-Arabi robbed Dani Ceballos and curved a fine shot beyond Bernd Leno.
Arsenal looked like they were going to rue another avoidable error, but two goals in six minutes late in the day claimed a significant first-leg advantage. First, Gabriel rose majestically to loop a header into the far corner before substitute Mohamed Elneny drilled a superb strike in off the far post five minutes from time.
Next up, Arsenal have the small matter of the North London derby at home to Tottenham on Sunday. The Gunners will then reconvene with Olympiacos for the second leg of this tie next Thursday.