Pat Fenlon’s Hoops, with 10 changes from their 3-0 win over Galway United on Friday, struggled early on to settle on the uneven surface at Stradbrook.
And it was Cabinteely’s Kevin Knight who had the game’s first real chance on 17 minutes when planting a free header wide from John McKeown’s corner.
Rovers eventually came alive to take the lead on 58 minutes. Defender Cornwall’s diagonal ball found the run of winger Sean O’Connor who headed over advancing keeper Whelan.
Six minutes later a defensive clearance ricocheted off midfielder Miele to fly into the home net.
CABINTEELY: Whelan; Campbell (Cairns, 74), Ekanem, Maloney, McGlynn; O’Neill (Mazono, 77), Finnegan, McKeown, Knight; Buckley (Foley, 68), Pender.
SHAMROCK ROVERS: Murphy; Clancy, Blanchard, Cornwall, Byrne; Miele, R. Brennan, McPhail, S. O’Connor (D. Kavanagh, 78); McCabe; McCaffrey (Waters, 62).