Holders Antrim swept to a massive 7-17 to 1-5 win in the Ulster Under-21 Hurling Championship final at the Athletic Grounds on Wednesday night.
The Saffrons built up a 1-7 to 0-2 led by half-time, substitute Sean McAfee scrambling in a 27th-minute goal.
Niall McKenna and Saul McCaughan grabbed two goals in the space of 30 seconds early in the second half
Down got a goal from Conal Fitzsimmons but Clarke, Connor Burke (2) and McCaughan found the net for Antrim.
Down simply had no answer to the class and quality of a Saffron side winning the championship for a sixth successive time.
Two points in the opening two minutes from Peter Mason and Eoghan Sands proved to be Down's lot for the first half.
Antrim slipped into gear following a slow start, and were 0-4 to 0-2 ahead by the 23rd minute, with Ryan McCambridge, Ciaran Clarke and Daniel McKernan all hitting the target.
Sean McAfee came off the bench to scramble home a goal with his first touch, and Clarke brought his tally to three as the Saffrons built up their eight-point interval advantage.
Quick goals by McKenna and substitute McCaughan left Down with an impossible task
They did pull back a goal through Fitzsimmons, but the floodgates were yet to open as Clarke, Connor Burke (2) and McCaughan piled on the agony with further goals.
Antrim: C Butler, T O Ciarain, P Burke, F Donnelly, J McGreevy (0-1), E Campbell, M Bradley, D McGuinness, M Dudley (0-1), D McCloskey (0-1), R McCambridge (0-1), N McKenna (1-2), C Clarke (1-6, 0-2f), D McKernan (0-2), Stephen McAfee (0-1).
Subs: Sean McAfee (1-0) for McGuinness, S McCaughan (2-1) for Donnelly, C Burke (2-0) for McCloskey, E McCaughan (0-1) for Stephen McAfee, M Connolly for Bradley.
Down: S Savage, M Conlan, M McCullough, G O'Neill, C Taggart, C O'Neill, J McGrath (0-1), J McManus, R Brannigan, P Mason (0-1, f), B Nicholson, C Egan, L Savage, S Mageean, E Sands (0-2).
Subs: B Byers for O'Neill, C Fitzsimmons (1-1) for L Savage, A Scott for McManus, J Doran for McCullough, D Mallon for Mageean.