There was a moment of unrest between City's players in the second half when Vincent Kompany, excellent at centre-back, read the riot act to Yaya Toure.
But Mancini said: "I'm happy with them arguing on the pitch. It's better we argue there, it shows we want to win. It's better they do that than stay silent.
"I'm also very happy with the fans, I must say thank you to them. Their support is always there for the team. It's very important."