Arsenal boss Mikel Arteta says his side ‘showed personality’ in their 3-1 away victory over Olympiacos.
The Gunners took the lead in the first half as Martin Odegaard bagged his first goal for the club.
He rifled a shot past Olympiacos keeper Jose Sa from long range.
Arsenal allowed the Greek champions back into the game in the second half through another calamitous error.
Dani Ceballos was caught in possession after receiving the ball from Bernd Leno.
Youssef El-Arabi then swept the ball past Leno with a curling strike.
The Gunners responded with goals from Gabriel and Mohamed Elneny to take control of the tie.
Speaking after the win, Arteta told BT Sport (via BBC Sport): “We started the game really well, really dominant and creating a lot of chances.
“We gave them a goal trying to play out from the back but then we reacted well to score two more goals. Overall, a really positive result but we have to stop making the errors that are costing goals because we cannot sustain that.
“It isn’t about concentration, it is about when you play the ball. It is not about stopping the way we play because this is us.
“We were really solid, really dominant. We showed a lot of personality to come here and dominate like we did. The next thing is to do that for 90 minutes and give nothing to the opponent.
“This is half time and anything can happen. Full focus. We start 0-0 again in the second leg and try to win the game.”
The victory puts Arsenal in the driving seat of their Europa League round of 16 clash.
Arteta will be pleased with the way his team responded to Olympiacos’ goal.
Gabriel rose tall from a Willian cross to restore their lead.
Elneny was then allowed to bear down on goal and fire the ball past the keeper, securing the win.
Arsenal’s next match is against Spurs in the North London derby on Sunday at 16:30.