Justin Browne’s scores had kept Donegal in check before Roscommon took charge in the final ten minutes of part one, which yielded 2-4 for the rampant Rossies.
Liam Kilcline kick-started the purple patch with a fine solo goal in the 20th minute. That was followed by a clever finish by Gavin Downey, while scoring ace Robbie Fallon’s points helped send Roscommon in 2-8 to 0-3 ahead at the intervak.
Donegal kept up the fight, but Roscommon just proved too strong.
Scorers for Roscommon: R Fallon 0-8, L Kilcline 1-3, G Downey 1-1, C Mulry 0-2, G Egan, T Mullen 0-1 each.
Scorers for Donegal: J Browne 0-5, S Doherty 0-1.
ROSCOMMON: K Kellehan; C Duignan, S Naughton, G McDermott; P Dolan, C Dolan, S McCormack; P Brennan, G Egan; T Mullen, A Donnelly, G Downey; R Fallon, L Kilcline, C Mulry.
DONEGAL: D Lafferty; F Lennon, D McLaughlin, M Callaghan; J Browne, S Gallen, B Lafferty; C Parke, C Harkin; J Alvey, K Meehan, C McCormack; C Grant, G McGrath, C Gallen.
Subs: E McGrath, S Nelson, S Doherty.