The visitors enjoyed a dream start when Michael Magill scored a goal after just 50 seconds. However, after an exchange of points between Paddy Cunningham and Darren McDermott, the hosts then took over.
Following points from Cathal Cregg and Ger Heneghan, Cregg set up Conor Devaney for a goal in the 12th minute. Roscommon led 1-6 to 1-2 at half-time.
Points from McDermott and Cathal Dineen stretched the lead to six by the 52nd minute. Cunningham converted a 55th-minute free and had the chance to bring Antrim back into the game four minutes later but saw his penalty well saved by Claffey.
Scorers for Roscommon: D McDermott (0-4, two frees), C Devaney (1-0), G Heneghan (0-2, one 45), C Dineen (0-1), I Kilbride (0-1), K Higgins (0-1), C Cregg (0-1).
Scorers for Antrim: P Cunningham (0-4, three frees), M Magill (1-0), M McCann (0-1), T McCann (0-1).
ROSCOMMON: G Claffey; S McDermott, N Collins, C Dineen; I Kilbride, N Daly, S Purcell; M Finneran, K Higgins; D Keenan, C Cregg, N Kilroy; C Devaney, G Heneghan, D McDermott.
Subs: K Mannion for Higgins (47), S Kilbride for Devaney (53), C Compton for Cregg (61), D Rogers for Dineen (65).
ANTRIM: C Kerr; P Gallagher, D O’Hagan, S Finch; T Scullion, J Crozier, J Loughrey; M McCann, C Kelly; T McCann, M Magill, M Armstrong; B Neeson, M Sweeney, P Cunningham.
Subs: A Gallagher for Kelly (32), K O’Boyle for Gallagher (half-time), M Johnson for O’Hagan (half-time), C Murray for Armstrong (47).
Referee: D Corcoran (Mayo).