Eze hit a superb strike to open the scoring as Arsenal eased into the quarterfinals.
Afterwards, Arteta discussed the midfielder at length and his growth over the season. He stated: "I think we started the game so well. We were a threat from every angle, their 'keeper maintained them in the game I think, and we needed a magical moment from Ebs to score a wonderful goal, a wonderful strike, to give us the lead.
"He is playing I think every three days now, he has a rhythm, an understanding with his teammates as well, what we want, and especially his level of activity, with and without the ball - in the spaces that he moves and the purpose that he's showing every time he's in and around the box as well. It's a reason why he's here - to create those kind of moments.
"I think he's building a better chemistry, a better understanding with all of them, and we start to understand him much better and then, yes. When you start to make a good game, a good action - an action that can win you the game - that lifts your confidence as well, and that's what every player needs."
Arteta added, "Comparing the minutes he's playing now with his career, he's playing much more now than in any other season, so that tells you as well the consistency he's showing, he's always fit. Today he had to come off - he has a lot of minutes in him, but he's handling the pressure of the situation and the expectation very well."
On Eze's pressing off the ball, the manager also said: "Without that, you don't have any chance to play in this team. Because everybody does it, and that's the magic of it and the reason why we are so consistent in winning matches and preventing the opponent to score. He can do it - if he couldn't do it, I would never demand it - he can do it, he's willing to do it, and he's doing it better and better every day."