Down set up a Dr McKenna semi-final clash with Cavan when they prevented UUJ from becoming the first college side ever to qualify for the last four at Newry.
Down looked more potent going forward throughout the opening half, but two superb saves from UUJ goalkeeper Michael McAllister, who denied Kevin McKernan and John McAreavy, kept the students very much in touch.
The sides were level on five occasions in the opening period, with Mark Lynch hitting five for UUJ, and John Fegan and McKernan on target for the Mourne men, who drew level in stoppage-time through Ronan Sexton, making it 0-6 each at the break.
Sexton had levelled again for the eighth time when wing-back Kevin McGuigan got on the end of a sweeping move to blast to the roof of the net with 18 minutes to play.
And sub John Clarke sealed it with three delightful late points.
Down scorers: K McGuigan 1-0, J Fegan 0-4 (4 frees), K McKernan, R Sexton, J Clarke 0-3 each, D O’Hanlon, L Doyle (free) 0-1 each.
UUJ scorers: M Lynch 0-9 (7 frees), T McCann 0-2, A Moran 0-2, J McGovern, R Mulgrew 0-1 each.
