Arsenal led 2-1 after two goals in three minutes before Danny Graham scored in the 87th minute after being set up by Sung-Yeung Ki.
Wenger said: “They have quality to attack but I hoped we would have enough resources at 2-1. We were a bit nervous at the corner, but it was an exciting game to watch.”
“I felt we could have cleared the first ball on the cross. I don’t know why we didn’t do it. We were guilty for the second goal.”
The north Londoners were behind after Swans substitute Michu left Per Mertersacker for dead to slot the ball under Wojiech Szczesny. Lukas Podolski and Kieran Gibbs put visitors in the lead, with it being the first goal of the season for the latter.
The Gunners boss continued: “I feel we have shown quality, heart and character especially in the second half. But it’s frustrating to concede a goal in the way we did it. We were very lethargic on the corner. Swansea found the resources to score two goals.”
While he was keen to champion scorer Gibbs, saying: “Gibbs display was fantastic and he was one of the players who kept going forward. You can see there is a lot more coming from this boy and I’m happy for that.”