The game turned when Robbie Keane's penalty was saved by Manuel Almunia in the 72nd minute.
Having gone 1-0 down just three minutes into the second half, Robbie hit the crossbar after 66 minutes and seconds later, Dimitar Berbatov made it 1-1 from a tight angle.
We were on top and the penalty gave us the opportunity to take control but just a few minutes after Almunia's save, the tide had turned back to the home side as Nicklas Bendtner headed home from Cesc Fabregas' corner for what turned out to be the winner.
"Robbie's upset about the penalty and we're all disappointed," said Head Coach Juande. "He's normally certain with penalties but today he missed when we needed a goal - but these things happen.
"The game was very evenly balanced and we had that chance at 1-1, we didn't take it and Arsenal went on to win the game.
"To concede a goal from a corner when all 10 outfield players are in the penalty area isn't normal either and that mistake cost us, we shouldn't concede goals like that."
There were no surprises as Juande Ramos reflected a disappointed away dressing room after the 2-1 defeat at the Emirates.