The Gunners were hammered 6-0 at Stamford Bridge last weekend on Wenger's 1,000th game in charge and then conceded a last-minute own goal through Mathieu Flamini to draw 2-2 with Swansea in midweek.
But Flamini became the home hero on Saturday night, scoring a deserved second-half equaliser against a City side who dominated the first half and took the lead through David Silva.
Wenger has also refused to rule his side out of the Premier League title reckoning, although he accepts they are also in a battle to remain in the top four over the final games of the season.
He told Sky Sports: "What happened to us last week was a nightmare and on top of that we scored an own goal against Swansea so the dressing room was really, really flat on Tuesday night.
"I have to say the players were fantastic. The way we responded today with a lot of fight is absolutely marvellous, it shows the team has a really special mental quality.
"When you look at the results today you can see anything can happen. We may be far from the top but you have to continue with this period, and you never know.
"Sometimes you have to accept that in this league everybody can beat everybody."
Wenger felt his side were unfortunate not to go on and win the game, having recovered from City's dominance in the first period to emerge the stronger side in the second half.
He added: "I think we started nervy and Man City were more confident, so we were a bit on the back foot.
"Slowly we got into the game and in the second half we controlled the game and unfortunately couldn't score a second goal.
"We played higher up the pitch and controlled the game much better. I was confident we could win it, but with what we have gone through it was very important not to make a defensive mistake."