"I was anxious. I want my team to become more clinical as that will be better for us. I don't understand why we are missing chances. When you have six or eight chances you need to score more goals," The Sun quoted Mancini, as saying.
City bounced back after suffering a crushing 3-2 derby defeat last weekend to Manchester United, the paper said.
Mancini added: "When you lose, particularly against United, it's important to win again quickly."
The Toon lost for the sixth time in seven games.
Boss Alan Pardew said: "After half-time we completely bossed it. City were hanging in there but nicked the third goal. It's put us under pressure now before QPR come here, which is a big game." (ANI )