For me i would say it was Arteta, had another outstanding game although it got a bit spicy with some of the tackles flying in. Rosicky was very good but i thought he gave the ball away far too oftne especially when he was being surrounded by Dortmund players but it was his work that led to the goal. He lost the ball, managed to somehow get the ball back, passed it off to Ozil who was being more and more influential as the game went on and the rest is history.
Id also put Ramsey as MOTM for that goal he got, luckily he was quick enough to get ahead of Subotic and head the ball in.