Pepe registered a goal and two assists in the 4-0 victory.
Asked about Pepe after the game, Arteta said: "We just need consistency from him.
"Wide talented players in this league are not easy to get because obviously the most difficult thing to do is create things, but we've said some things and we need Nico to maintain game by game.
"He knows that and it's the way he was applying himself defensively in a few moments, he was top drawer.
"That's what he wasn't doing in the past and when he does that, the rewards in the other box come. He made a difference today."