Madueke was a late addition to the starting XI after Bukayo Saka broke down in the warm-up.
He said afterwards: “I didn't know what happened to B. In terms of the time I had before the game, it was not much, maybe five minutes to warm up and go out and play. It's the first time that's happened to me, so I was just happy that I was going to get to play from the start, to be honest.
“As an attacker, you always try and make an impact in an attacking sense, whether you can score or create goals or create chances, wreak havoc and pose a threat, so I'm happy that I was able to do that today.
“You’re always very happy when you win, and we won today, so it’s fantastic. Everyone's happy with a smile on their face.”
Madueke created Arsenal's opener scored by Martin Zubimendi.
He added, “It’s massive. Obviously, our last couple of performances in the Premier League haven't been the greatest in terms of results, but today was a real statement.
“We’re going to watch what (Manchester City and Aston Villa) do and focus on our game as well on Tuesday. That's most important for us.
“Adding confidence after a performance like this, not only just the win, but a really dominant performance. We're going into that game on Tuesday knowing what's at stake and knowing what we need to do.”