Wenger was confident this win would lift the gloom that has surrounded the club following the double departure of captain Cesc Fabregas and Samir Nasri, a winless start to the Barclays Premier League season and a raft of injuries and suspensions.
"We have been a little bit under pressure and for us not to play the Champions League and with the players who left, that pressure would've increased, understandably," he said.
"Since the beginning of the season, I feel a very strong, determined attitude within the team."
Admitting his relief, Wenger said: "We responded in a very positive way, even being down 1-0.
"We had a fantastic second half.
"I'm very happy because we kept composure.
"We kept dominating, playing the football we want to play."