Moments before Andrey Arshavin fired Arsenal into a 40th minute lead at Old Trafford, Fletcher clattered into the Russian schemer inside the box.
Referee Mike Dean waved played on, with United manager Sir Alex Ferguson confident the right decision was made during the champions' 2-1 win.
And Fletcher believes that, after missing last season's UEFA Champions League final after being harshly sent off against Arsenal in the semi-final second leg, he was owed a slice of good fortune.
Heat of the moment"I went for the challenge and felt I got the ball," said Fletcher.
"Maybe I am due a bit of luck after what happened in the Champions League semi-final last season.
"These things happen in football. I know I played a bit of the ball and a bit of the man, but in the heat of the moment you are not 100% sure."
Ferguson felt Fletcher produced a man-of-the-match display in helping United come from behind to beat Arsenal, and the Scotland international admits he enjoys facing the club's rivals.
He added: "I enjoy the challenge of playing against Arsenal. I did my usual thing. I got about people and tried to raise the tempo of the game.
"I put tackles in and tried to get the guys playing a little bit. It is no different to what I do in other games, but it sometimes gets noticed more in big games."