Goals from Graham Cummins and new signing Shane Barrett cancelled out Pat Huban’s early effort for Mervue, before Davin O’Neill and Cummins with his second wrapped up the points in the second half.
On five minutes the home side’s positive start got its reward, when Huban crashed a half-volley into the back of Mark McNulty’s net off the crossbar.
After a sticky start, Cork got to grips with Mervue’s five-man midfield and levelled midway through the half, Cummins converting Barrett’s cross.
Keeper Ger Hanley was unable to stop Cork taking the lead as Barrett ran onto Cummins’ flick on, rounded the keeper and found the net, sending City in 2-1 ahead at the break.
City put the game beyond doubt seven minutes after the restart, when O’Neill poked home a cross from Neal Horgan on the right. Then Cummins claimed his second, this time Billy Woods providing the cross.
Substitute Dave Goldbey headed a consolation for Mervue on full-time.
MERVUE UNITED: Hanley; Crehan, Curran, Elwood, Farrell; Connolly (Varley, 81), Tierney, Walsh (Goldbey, 63), Cunningham (Ludden, 81); Huban; Gaffney.
CORK CITY FORAS CO-OP: McNulty; Horgan, Mulcahy, O’Halloran, Meade; O’Neill, Duggan, Lordan, Woods (Lougheed, 87); Cummins (Morrisey, 87), Barrett (Cambridge, 79).
Referee: B Kelly (Offaly).