Limerick’s minor hurlers began their Munster campaign with a draw after Darragh Flynn’s injury time free saw Cork earn a draw.
Diarmuid Mullins’ side had led by five points going into the final quarter but Flynn fired over six points to see the game finish 0-19 to 1-16.
Cork had led by five points (1-4 to 0-2) after 13 thanks to Flynn’s 1-2 and points from Daniel Hogan and Paul O’Riordan.
Limerick rallied to level the game on 22 minutes thanks to three in a row from O’Neill and one each from Aidan O’Connor and Patrick Reale.
They then went in at the break ahead (0-9 to 1-5) with O’Connor landing a stunning second point of the half.
Limerick continued to impress in the second half with O’Neill causing damage every time he got possession.
The victory looked to be theirs as they were fully dominant going into the closing stages but Flynn’s heroics snatched a dramatic draw for Cork.
Scorers for Limerick: Cathal O’Neill 0-10 (9f), Aidan O’Connor 0-4, Adam English 0-3, Diarmuid Hegarty and Patrick Reale 0-1 each.
Limerick: Jack Franklin; Ronan Lyons, Michael Keane, Fergal O’Connor; Jimmy Quilty, Eathan Hurley, Colin Coughlan; Adam Murrihy, Patrick Kirby; Patrick Reale, Diarmuid Hegarty, Cathal O’Neill; Aidan O’Connor, Adam English, Patrick O’Donovan.
Subs: Liam Lynch for O’Donovan (49), Cian Casey for Reale (50), Conor Hanley Clarke for Murrihy (58).