Former Ulster head coach Neil Doak was part of the coaching team assembled by former Ireland No.8 Brian Robinson and their influences were evident in a memorable win.
In ideal conditions, two mobile, well-organised forward units created many attacking opportunities but it was right on the stroke of half-time that the stalemate was broken, Campbell scrum-half Dara Gaskin squeezing over for a try and a 5-0 interval lead after his pack laid siege to the opposition line.
Armagh stormed out on the restart with Zac Thompson kicking a penalty to cut the gap to two points.
But in the 50th minute Oscar Yandall’s errant kick was gathered by Campbell full-back Conor Rankin who sprinted in from 25 yards before converting his own try for a 12-3 lead.
A minute later Thompson reduced the deficit, but in the 64th minute Campbell capitalised on a well-worked line-out.
From the resultant ruck winger Will Davis ran a forceful line to touch down, Rankin’s conversion easing the Belfast team 19-6 in front.
But Armagh’s refusal to concede was brilliantly emphasised by a spectacular last-minute converted try following a mazy, determined run by replacement Ben Lavery. However, it proved too little too late.
M Campbell; O Webb, Z Thompson, M Reaney, N Jennings; R Morrow, A Johnston; J Chapman, J Treanor (capt), A McAlpine; J Agnew, S King; A Woods, R O’Neill, G Crawford
S Rainey, A Edgar, J Roberts, R Finlay, J King, B Lavery, C Whiteside, P Taylor.
C Rankin; W Davis, J MaCartney, B Power, R Tinsley; O Vandall, D Gaskin; J McKee (capt), H Jenkins, P McAlpine; O Kiernan, J Harrison; J Stinson, T Olaniyan, S Robinson.
J Gildea, M Carlisle, M Poor, J Johnston, J Brennan, L Yandall, H Owens, K Robertson.