Ringmahon made a rip-roaring start, with Jordan O’Regan going close before Evan O’Brian’s shot rattled the post.
But Ballincollig took the lead in the 15th minute with Ronan Barrett’s excellent header from Shay Daly’s corner.
Ringmahon had a great chance to level on 25 minutes when Christopher Hull’s effort flew just over.
Two minutes later, they were back on terms when Ireland U18 captain Troy O’Sullivan’s glancing header went in via the post.
Robbie O’Leary saved well from Collig’s Darren Murphy, as the sides went in level.
Early in the second half, Hull headed wide for Ringmahon before Ballincollig’s Whelan was denied by another excellent O’Leary save.
Just as it looked like Ringmahon were getting on top, up stepped that man Whelan to slot Ballincollig in front.
Ringmahon applied the pressure in the late stages, but Kearney was unable to get a vital touch on a great ball in by Dalton.
Ballincollig sealed it through Darren Murphy on the counter-attack, as he rounded O’Leary and neatly finished to spark wild celebrations.
Robbie O’Leary; Aaron Quilligan, Mark O’Callaghan, Troy O’Sullivan, Aaron Ahern; Evan O’Brien; Christopher Hull, David Hurley, Gordon O’Meara, Ciaran Kearney; Jordan O’Regan.
David Dalton for O’Meara (62) , Cameron Harlson for O’Callaghan (85). Cillian Farmer, Caoilte Hayes , Jack McCarthy, Keelyn Cotter(not used).
Shane Hogan, Shane Dunne, Evan Kenefick, Jordan O’Connor, Stephen Keane; Shay Daly; Finonan O’Donovan, Matthew Whelan, Kevin Crowley, Ronan Barrett; Darren Murphy.
David Courtney for Dunne (70) , Mark Walsh for Barrett( 79) ,Darren Forde for O’Donovan(89) , Daire O’Leary, Tony Hogan, Nathan O’Callaghan, Eoghan Curran (not used).