Eze opened the scoring as they won 2-0 on Wednesday night with Leandro Trossard also on the scoresheet.
He said afterwards, "It's a special day to get my first goal and to win. It's important to get through to the next round; that was the main thing. But it's a special day for me.
"I just somehow found a space inside the box. So I knew that I didn't have time to take many touches. So I was just looking to get a shot off; that was the main thing. Fortunate, and a lot of hard work behind it, but it's a good day."
Eze added, "Coming to a place like this, away from home, in difficult circumstances, but finding a way to win, that's the most important thing. You take it into the next one."
Gunners manager Mikel Arteta also said of Eze on the night: "He played very centrally against a team that's obviously with a 5-4-1; they are a super compact inside. It's not easy to find spaces, but he's very capable with the ball.
"You've seen that in another three or four actions that he's completely through, and playing people through. He still needs a little more time with those guys to understand the timings, especially the things that he needs to do.
"Then actions like that will be more consistent and better for us. In general, very good - there is still a lot more to give, I think."