Former Premier League official Dermot Gallagher has said that there were no issues with Manchester United's winning goal in the derby showdown with Manchester City.

On Saturday evening at the Etihad Stadium, United fought back from two goals down to record a 3-2 victory over City thanks to Chris Smalling's volley from an Alexis Sanchez free kick.

The centre-back was marginally onside when the ball was delivered into the box and Gallagher has defended suggestions that the assistant would not have been able to definitively identify that the goal was scored legally.

Gallagher told Sky Sports News: "What I would say in defence of the assistant - and I do not have to defend him because I believe he has got it right - is that everybody watching it would say that there is no way an assistant can be convinced he is offside.

"That is the difference. You have to be convinced he is offside and in that situation you cannot be 100% convinced he is."

Gallagher acknowledged that City were unfortunate not to be awarded a penalty later in the fixture.