A point by Kieran O'Callaghan three minutes into injury-time secured Limerick’s first win of their Allianz NFL Division 3 campaign.
The hosts were quicker out of the traps and inspired by young starlet Ian Ryan, who finished with 0-05 to his credit, led by 0-06 to 0-05 at the break.
A purple patch mid-way through the second half saw Limerick open up a three-point gap, but Roscommon drew level when the brilliant Gary Cox cut through the Treatymen's defence before rifling a low shot to the net.
The Rossies then went two points clear, though Limerick were furious that a point by Conor Devaney was scored while the visitors had 16 men on the pitch.
But Limerick composed themselves and points from Ger Collins, dual star Stephen Lucey and Stephen Lavin had them ahead as the clock ticked past 70 minutes.
Roscommon appeared to have earned a point when Karol Mannion landed a point from distance two minutes into stoppage time.
Limerick were not to be denied, however, with Ballylanders duo Jimmy Barry Murphy and O’Callaghan combining before the latter split the posts for the decisive point.
