Arteta also insisted his team won’t stop playing out from the back.
The Gunners put one foot in the quarter-final, thanks to goals from Martin Odegaard, Gabriel and Mohamed Elneny.
However, Arsenal only managed to gain their two-goal advantage after conceding a soft equaliser, with Youssef El-Arabi scoring after intercepting a lazy pass from Bernd Leno.
Arteta told BT Sport after the final whistle: “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 and we start 0-0 again in the second leg and try to win the game.”
