A goal from substitute Caolan McConville proved the decisive score for Killeavy as they saw off Ballymacnab by five-points.
The home side finished with a flurry, claiming 1-5 in the closing stages to get over the line and top Group A.
The Nab has led by three points heading into the final ten minutes but failed to register another score.
Ballymacnab made a blistering start to the game, soaring into a three-point lead in the opening minutes.
Oisin McGivern, Jack Grugan and Pauric Gribben also split the posts inside the first five minutes.
But Killeavy earned three in a row themselves. Miceal McNamee (free), Callum O’Hare and Rory Kearney tied things up.
Ryan Watters traded scores with Cathal Boylan, who kickstarted another scoring spree for Killeavy.
Ciaron O’Hanlon and Ronan McGuinness (two marks) but Tommy Coleman’s side ahead by three points.
Watters exchanged efforts with O’Hare while McGuinness (free) and O’Hanlon added further scores for the hosts.
The Nab finished with a point from a Watters free to see them behind by four at the break. 0-10 to 0-6 at half time.
Once again, the Nab started brightly as a Rory Grugan brace, after he swapped scores with McGuinness, left two the difference.
Oisin McGivern claimed a second, sandwiched by Killeavy points from Lee Rice and McNamee.
Ryan Watters then rattled the net, reacting quickest to a Shea Magill save, to drag the Nab back into the game.
They followed it up with three on the trot from Finnen Maguire and the Hughes brothers, Kieran and Pearse.
The visitors didn’t score again however, as Killeavy took control with scores from Shea Magill (free) and Boylan.
Caolan McConville punched home an Oisin King pass into the square to give Killeavy the lead once again.
O’Hanlon, Rice and Magill (free) all chipped in with further scores to see Killeavy through to the last eight.
Ballymacnab finish in second place, with Dromintee in third following their win over Maghery. That means Maghery exit the championship.