In a game Sligo couldn’t afford to lose, Marren scored seven first-half points for the rampant home side, who were put on the road to victory when David Kelly goaled 35 seconds after the re-start to put 11 points between the sides, 1-12 to 0-4.
Armagh, who were already promoted ahead of their trip south, struggled throughout but lively corner-forward Andrew Murnin, who scored 1-1, was one of the few positives.
Sligo, with veteran defenders Ross Donovan and Brendan Egan on form, led from the fourth minute and their slick, free-flowing style saw them eight points up at the break, 0-12 to 0-4.
Marren was denied a goal just before half-time when Armagh net-minder Paddy Morrison put the attacker’s goalbound shot out for a ‘45’.
Adrian Marren (0-8, 5f), Mark Breheny (0-5, 5f), David Kelly (1-1), Pat Hughes (0-1), Neil Ewing (0-1), Cian Breheny (0-1), Niall Murphy (0-1), Keelan Cawley (0-1)
Andrew Murnin (1-1), Eugene McVerry (0-4, 4f), Gavin McParland (0-2, 1f), Stephen Harold (0-1)
S Gilmartin for C Davey, 54; C Kerins for N Ewing, 65; N Gaughan for B Egan, 70; J Martyn for R Donovan, 70; S Coen for D Kelly, 70; P Clarke for A Marren, 70+1
A Findon for P Carragher, h-t; T Kernan for B Donaghy, h-t; M Shields for E McArdle, h-t; K Dyas for P McKenna, 50; O Mac Íomhair for G Parland, 52; N McConville for S Forker, 60
A Devaney, D Maye, K McDonnell, R Donovan, K Cawley, E Flanagan, B Egan, N Murphy, C Breheny, N Ewing, M Breheny, C Davey, D Kelly, P Hughes, A Marren
P Morrison, A Mallon, C Vernon, J Morgan, C McKeever, E McArdle, M Murray, S Harold, P Carragher, B Donaghy, P McKenna, E McVerry, S Forker, G Parland, A Murnin
Derek Fahy (Longford)