The Gunners' spluttering Premier League title challenge suffered another major blow as Mathieu Flamini's last-gasp own goal forced his side to settle for a point.
Wenger's side looked set to bounce back from Saturday's humiliating 6-0 defeat at Chelsea after two goals in the space of 60 seconds midway through the second half from Lukas Podolski and then Olivier Giroud erased Wilfried Bony's early opener at Emirates Stadium.
But Flamini deflected the ball into his own net from close range in the final moments to leave Arsenal six points behind leaders Chelsea with only seven games left.
"It's really unlucky but we have to focus on the next game now and live with the result," the Frenchman told Sky Sports.
"They defended well, which all teams do now. We need to be patient and not concede the second goal which I thought we did quite well.
"In the space of two minutes we scored two goals but after that you could see that our drive going forward was less.
"We were possibly more concerned about keeping the score (as it was) because of what happened on Saturday but we were too conservative."