Danny Graham, on-loan from Middlesbrough stooped to nod in his sixth goal in six games after only five minutes. Jeff Smith, Joe Garner, Kevin Gall and Graham again should have added to the tally, with City's on-loan keeper John Ruddy pulling off some great saves on his debut. But slack marking from the home side on the stroke of half-time saw Kevin Betsy cross for the unmarked Jamie McCombe to head in easily.
Deflated by the goal, Carlisle were now easy pray for City who went in front after 65 minutes through the superb Enoch Showunmi. David Noble, dangerous all game, delivered a superb pass on the blind side of Carlisle's full-back David Raven leaving Showunmi to fire home between Keiren Westwood's legs from a tight angle.
Carlisle threw on three substitute strikers in the search for an equaliser but it was City who made the game safe with an unstoppable strike from Bradley Orr. The full-back pushed forward and cut inside his marker onto his left foot and struck a bullet of a shot into Westwood's top corner from the edge of the penalty area.