"I thought we performed with a focus this evening," Wenger told Sky Sports News.
"We played with pressure from the first moment to the last and we didn't make one mistake. We had the attitude that didn't give them any room to make chances. Overall it was a mature performance.
"I was concerned after we scored as we had a long time to go before full time, but after [the goal] we created chances to score and had a few dangerous situations. They tried a little bit, but it was a question of keeping the team focus."
The result leaves Arsenal top of Group F, level on points with Napoli.