Manchester City will face Manchester United in the FA Cup semi-final courtesy of Micah Richards' winning header against Reading on Sunday.
The defender headed the only goal of the match at Eastlands and booked a derby date at Wembley in April.
Reading, the Championship's 10th-placed club, arrived at Eastlands without three of their first-choice back four, including former City defender Matthew Mills, and regular goalkeeper Adam Federici.
Jobi McAnuff was the early cause of concern for City as the left-sided winger delivered a low cross, which had to be cleared on the slide by Joleon Lescott, before a jinking run beat Shaun Wright-Phillips and Richards.
Wright-Phillips, along with captain Carlos Tevez and Nigel de Jong, was back in Mancini's starting XI and the former's diagonal run to collect David Silva's 15th minute pass was the first moment of excitement for the Sky Blues, but they were to be denied a shooting opportunity by an offside flag.
Vincent Kompany could have no complaints in the 21st minute when he became the first player to go into referee Lee Probert's book after clattering into Hunt in an aerial collision.
Silva was arguably the best player on the pitch and was attempting to deftly pull the strings from deep areas, releasing Yaya Toure on the half-hour only for the Ivorian to be denied by McCarthy's knees.
Reading almost pressed the self-destruct button immediately after half-time when Aleksandar Kolarov's in-swinging corner was inadvertently headed goal-wards by Shane Long, who was grateful to see team-mate Jay Tabb clear off the goalline.
Richards was booked for bringing down McAnuff, but City were still the attacking force, although their wastefulness remained as Wright-Phillips decided against a shot when breaking down the right and his harried pass caused Tevez to scuff an effort.
Patrick Vieira was already set to be replaced, but the decision proved well-timed after the Frenchman was clattered by a challenge from Long which merited a booking from Probert.
Shortly after, the home side had their breakthrough in the 74th minute when Silva delivered a perfect corner from the right and Richards managed to lose his marker before out-jumping Zurab Khizanishvili to power an unstoppable header past McCarthy.