Manchester City goalkeeper Joe Hart insists there was nothing wrong with the wall for Manchester United striker Robin van Persie's derby winner.

Hart's own manager Roberto Mancini blamed his goalkeeper for setting his wall up incorrectly moments before Van Persie's free-kick found the bottom corner, courtesy of Samir Nasri's outstretched leg.

"There was no problem with the wall," Hart told the Daily Mail. "It's plain to see what happened. The ball was coming straight into my midriff. If it doesn't take a deflection it lands in my hands. But sometimes things happen.

"I don't care what other people say, I know what I'm doing. I know how many people I want in my wall. It cuts you deeply. It will have cut every City fan in that stadium.

"Inches and centimetres make the difference at this level but I have looked at the tape. It's a freak goal but it's nothing new. We train for these things and sometimes it works the other way.

"I have had plenty of times when it has worked in my favour. There have been plenty of times when a player has had all the praise for scoring a great goal. People will say, 'What a wonderful goal, he is the best player in the world'. But deep down inside you know you probably should have saved it. But nobody says that, they don't realise. So it cuts both ways. It's life."