Gael Clichy opened the scoring with an own goal before Gabriel Agbonlahor secured the win for Villa.
Wenger said: “It was a very bad afternoon because we were not sharp physically and beaten everywhere in the first half.
“I felt overall Villa were the better side. It is frustrating because we played at a kind of pace today that is not our pace. Villa played very well, but we were not sharp or incisive enough.
“We can play very well, but at the top level performances have to be consistent. I always say the first sign of quality is consistency, so this was frustrating after beating Manchester United.”
