Laois somehow managed to escape from Dr Hyde Park with a draw as late goals from Evan O’Carroll and Kieran Lillis earned Mike Quirke’s side a share of the spoils.
The comeback was ignited by a 'wonder goal' from O’Carroll, who ended up with a personal tally of 1-6, as an error-ridden contest ticked into injury-time.
But Laois weren’t finished yet and when Ross Munnelly floated a last-gasp free on top of the Roscommon defence, possession somehow found its way into the hands of Lillis, and the Portlaoise player managed to direct his effort beyond Colm Lavin.
Laois played the better football during the opening half, taking advantage of the new rules to procure 'advance marks' for Colm Murphy, Lillis and O’Carroll. But it was the hosts that grabbed the decisive score when Brian Stack fed Niall Kilroy for the game’s opening goal after 34 minutes.
The visitors trailed by 1-7 to 0-9 at half time but Lillis soon brought them level. Roscommon shook themselves with points from Cian McKeon (free), Niall Daly and Donie Smith (free).
Ross Munnelly’s 61st-minute free restored parity once more before Roscommon appeared to grab the contest’s match-defining score. Kilroy was hauled down by Mark Timmon for a penalty, a foul that resulted in a black card for the Laois full-back.
Enda Smith duly converted, and when the same player and Hubert Darcy (a free) tagged on points, Roscommon looked to have disappeared over the horizon.
But Laois hadn’t given up the ghost, and a moment of magic from Man of the Match O’Carroll gave them renewed hope when he sent an unstoppable shot to the roof of the net from 25 metres in the 70th minute.
Noel Gately and O’Carroll exchanged points before Lillis stunned the hosts at the death.
Scorers for Roscommon: E. Smith (1-2, 1-0 pen), D. Smith (0-4, 0-2 frees, 0-1 mark), C. McKeon (0-3, 0-2 frees), N. Kilroy (1-0), N. Daly, S. Killoran, C. Cregg, H. Darcy (1 free), N. Gately 0-1 each.
Scorers for Laois: E. O’Carroll (1-6, 0-2 ’45, 0-1 free, 0-1 mark), K. Lillis (1-3, 0-1 mark), C. Murphy (0-1 mark), R. Munnelly (0-1 free, 0-1 mark) (0-2 each); M. Keogh (0-1).
ROSCOMMON: C. Lavin; D. Murray, B. Stack, G. Patterson; P. Scott, N. Daly, R. Hughes; T. O’Rourke, S. Killoran; N. Kilroy, E. Smith, F. Cregg; D. Smith, C. McKeon, C. Cregg.
Subs: C. Daly for Hughes (44), H. Darcy for Killoran (blood sub), H. Darcy for F. Cregg (60), C. Lennon for C. Cregg (63), N. Gately for D. Smith (66), D. Ruane for O’Rourke (70).
LAOIS: N. Corbet; T. Collins, M. Timmons, G. Hanrahan; S. O’Flynn, R. Pigott, P. O’Sullivan; K. Lillis, J. O’Loughlin; S. Byrne, M. Barry, E. Lowry; M. Keogh, C. Murphy, E. O’Carroll.
Subs: C. Healy for Collins (47), R. Munnelly for Murphy (49), D. O’Connor for Keogh (49), G. Walsh for O’Loughlin (53), G. Comerford for Lowry (66), B. Byrne for Barry (70).
Referee: C. Branagan (Down).