The Gunners were undone by two late Michu goals in a thoroughly deserved win for the Swans, and Wenger admitted that the result was a big blow to him at the start of a crucial month for his side.
Arsenal now sit twelve points from top spot in the table, and Swansea overtook Wenger's side with the victory.
"We gave it away by not being creative," Wenger said.
"It's a concern because we didn't create a lot, we ran against a wall, our passing was not sharp and was not quick enough. We looked jaded.
"It's a big blow because we wanted to start December well. Games come quickly and we have to find the quality of our game. The way we played today is not how we want to play football."
Speaking on the subject of vociferous boos from the crowd, Wenger said: "Fans have an influence on us, but it is down to the team to get the fans behind them, the way we play has to create that.
"I can understand that [the boos] when we lose games the way we lost that."