"We had gone so long unbeaten that it took us a while to digest it. But the first victory since then is important to get back to our normal confidence level.
"Local derbies are either completely locked with no chances or completely crazy. This time, you got the crazy version."
While Wenger was delighted with his team's response, he admitted his concern at their vulnerability to set-pieces, especially in the continued absence of Sol Campbell through injury.
"I'm not too happy that we conceded four goals but derbies are a little bit special," he added.
"It's strange as we had the best defence in the league last season with the same back-four. But we're a bit smaller as a unit now."
Wenger declared: "It was important to get the three points. We had a hangover after the Manchester United game.