The Gunners made it to the knockout stage, thanks to a late goal by Danish striker Nicklas Bendtner.
Although he stripped compatriot Gallas of the armband days ago, Wenger was satisfied with the veteran defender's performance.
"I believe his focus was great," said Wenger after the Champions League encounter.
"He wanted to do well and you could see he was completely committed in the game. Overall, I feel he did well."
The Arsenal boss was also glad with the supporters' attitude towards the under-fire center-half.
"The crowd responded well. Somewhere, they acknowledge that he was a committed captain and I was very happy that the crowd reacted in this way to him," he added.
Despite their success in Europe so far this season, Wenger’s men have been recently condemned to two consecutive Premier League losses to Aston Villa and City, which could dent their title hopes.