After the disappointment of failing to win promotion back to Division 1B, losing a manager and then the Christy Ring Cup final replay defeat by Meath in Croke Park, the Saffrons badly needed this victory at Owenbeg.
The game was right in the mix until Armagh midfielder James King was sent off for a second yellow card offence after 58 minutes.
Antrim took advantage, outscoring Armagh by 2-5 to 0-2 in the last 15 minutes.
It was competitive in the opening 20 minutes until Antrim bagged three goals in a six-minute spell through John Dillon, Conor Carson, and Ciaran Clarke.
King buried a shot into the top corner for a spectacular Armagh goal in first-half injury time to leave them 3-14 to 2-8 adrift at the break.
Eoin McGuinness scored two goals for Armagh but Ciaran Clarke, who top-scored with 2-7, scored his second goal in the 45th minute to settle Antrim’s nerves.
Ryan Gaffney’s frees brought Armagh to within three points but King’s dismissal ended their bid for a first ever hurling title at this level.
C Clarke 2-7 (3f), J Connolly 2-2, J Dillon 1-2, C Carson 1-1, B McCarry, D McKernan 0-3 each, J McKeague, E McCloskey 0-1 each, C McNaughton 0-1 (f).
E McGuinness 2-2, R Gaffney 0-7 (7f), J King, D Coulter 1-0 each, F Bradley, C Carvill 0-2 each, C Corvan 0-1.
C O’Connell; S McCrory, N McAuley, B Graham; F Donnelly, P Burke, J McKeague; E Campbell, D McKernan; E McCloskey, J Dillon, J Connolly; B McCarry, C Carson, C Clarke.
O McFadden for McCrory (16), S Delargy for Graham (26), S McCrory for Donnelly (47), C McNaughton for McKernan (64).
S Doherty; C Clifford, A McGuinness, C Devlin; J Corvan, N Curry, F Bradley; K McKernan, J King; R Gaffney, C Carvill, D Carvill; D Coulter, E McGuinness, C Corvan.
P McKearney for Bradley (60), A Toal for D Carvill (68), O Curry for A McGuinness (68).
Eamonn Hasson (Derry).