"It was important for us to win this game because we had the chance to go into third position," Mancini said.
"Before the game I thought it would be difficult because it is not easy to beat Sunderland.
"They are a strong team who work very well and their manager knows everything. But we started the game brightly and that was important.
"I am surprised but I am happy. It is important that we scored five goals.
"It is possible (that it will give us confidence for our remaining games), but it is important now that we continue and go to Liverpool looking to win next Monday."