Mancini pulled no punches when discussing the performance of the officials, led by referee Peter Rasmussen, as Sergio Aguero saw his winning goal ruled out for offside in the final phases.
"The referee and the linesman were really poor. It was a penalty, and it was a goal," the angry Italian manager told ITV1.
"I told (Rasmussen) it was a goal and not offside.
"I think that we played well but conceded two goals from two corners.
"We made a lot of chances."