Roscommon continued their fine form with a facile defeat of Athlone IT, setting them up for a group decider against NUI Galway tonight.
Gerry Fallon and Naos Connaughton caused the home side huge problems under the dropping ball, the former scoring his side's opening goal.
Fallon saw a penalty crash off the crossbar, but Roscommon still went in 1-12 to 0-6 ahead at the break. Leitrim's faint hope were then crushed by goals from Tipp native Ronan O'Meara and Connaughton.
Scorers - Roscommon: Gerry Fallon 1-4 (0-1f), R O'Meara 1-3, N Connaughton 1-2, C Kelly & G Fallon 0-3 each, H Rooney & T Seale 0-2 each, M Kelly 0-1, AIT: S Molloy 0-3, G Wyer 0-2 (0-1f), S Hannon 0-2, C O'Loughlin, S Carroll, M Morris & M Egan (f) 0-1 each.
ROSCOMMON - N Fallon; I Delaney, P Kellehan, T Treacy; A Moore, M Kelly, C Shaw; S Kilcommins, J Moran; Gerry Fallon, R O'Meara, Gary Fallon; T Seale, N Connaughton, H Rooney.
Subs: L Kilcline for Treacy (37), C Duignan for Moran (41), C Kelly for O'Meara (47), O'Meara for Gerry Fallon (53).
AIT - W Power; C O'Connell, R Daly, D Gilkerson; S Carroll, J Fitzsimons, A Moran; J Kelly, G Wyer; S Hannon, S Molloy, C Gath; M Morris, C O'Loughlin, E O'Connor. Subs: M Egan for Kelly (HT), G McDermott for O'Connor (HT), P Staunton for Gath (HT), D Butler for O'Loughlin (33), M Naughton for Moran (55), D Hogan for Hannon (56).
REF - C Browne (Galway)