Down were a point ahead on a few occasions in the early stages but Paddy Cunningham’s goal after 22 minutes turned the game in Antrim’s favour.
Although Cunningham accounted for 1-3 of Antrim’s half-time tally, the Saffron had six different players on the scoresheet, with newcomer Philip Maguire catching the eye as they romped to a 1-9 to 0-6 lead at the break.
Mourne defender Dan McCartan received the only black card of the game after 60 minutes for pulling down Sean McVeigh, who had to be stretchered off.
Antrim dominated in the middle third and comfortably kept Down at bay — Mark Sweeney and Brian Neeson tagging on late points.
Scorers for Down: N Madine 0-4 (3f), D O’Hanlon 0-3 (2f), L Doyle 0-2 (1f), A Carr 0-1.
Scorers for Antrim: P Cunningham 1-3 (2f), P Maguire 0-2, CJ McGourty 0-1 (f), M Sweeney, M McCann, P Kelly, C Duffin, M Pollock, B Neeson 0-1 each.
DOWN: B McVeigh; D McCartan, J McCarthy, S McNamee; C Garvey, A Carr, R Boyle; K King, P Fitzpatrick; D Turley, L Doyle, D O’Hanlon; N Madine, B Coulter, S Bell.
Subs: B McArdle for Turley (30), D O’Hagan for Doyle (46), P Turley for King (55), E McCartan for D McCartan (60), G McArdle for Fitzpatrick (64), M Lively for Garvey (67).
ANTRIM: C Kerr; K O’Boyle, S McVeigh, N Delargy; M McAleese, M Johnston, J Lavery; M Sweeney, M McCann; C Murray, P Maguire, P Kelly; P Cunningham, C Duffin, M Pollock.
Subs: J Crozier for McAleese (43), B Neeson (0-1) for Duffin (44), CJ McGourty for Cunningham (53), T McCann for Kelly (53), C Kelly for McVeigh (60).
Referee: Stephen McNamee (Tyrone).