
Roscommon felt the full force of the cut-throat existence of life in Division One when they were caught on the line by Monaghan in Kiltoom.
A short kick-out from Darren O'Malley wasn't controlled by the Roscomon defence, allowing Conor McManus to intercept and apply the killer touch with a goal to give the visitors a 2-9 to 1-9 advantage in added time.
With substitute Daniel McKenna following up to pick off a second point, Roscommon's prospects of surviving the top flight have become much more compromised.
Roscommon had led by 1-5 to 0-2 at the break having played with the wind, the decisive moment coming on 27 minutes when Conor Devanney's delivery was perfectly measured for Ciaran Murtagh to steal in behind the Monaghan defence and invite a foul from Ryan Wylie that resulted in a black card for the corner-back.
Murtagh, who had already converted two frees for fouls on Cathal Cregg, tucked it away impressively despite Rory Beggan diving the right way and the home side had a bit of daylight on the back of a very strong wind.
Conor McManus had opened Monaghan's account with a magnificent 42 metre free converted off the ground but Beggan went a few metres better just after that to deflate a little of the rising enthusiasm among the 2900 crowd in Kiltoom.
Murtagh was subsequently black-carded, robbing Roscommon of one of their most potent attacking threats.
When Dermot Malone grabbed a goal early in the second half for Monaghan after Senan Kilbride's point at the other had extended the lead to seven, it was a sign of real intent from the the Ulster champions.
But despite dominating possession as the wind strengthened they struggled to make headway, eventually finishing with nine wides in the half.
It wasn't until a trio of points, two from Thomas Kerr and one from a McManus free midway through the second half that they picked up momentum again.
When Neil McAdam, who was subsequently sent off for a second yellow card, equalised on 67 minutes an away win looked inevitable but Fintan Cregg's conversion of a very difficult free after substitute Ultan Harney was fouled, gave Roscommon hope.
That hope was quickly extinguished however as Malone struck for a point almost immediately before a little touch of panic set in, allowing McManus, who had been so well contained by the home full-back line, to strike.
With a trip to Kerry next week Roscommon, who are returning to Division One for the first time in 13 years, are already struggling for survival in the knowledge that the smallest of mistakes can be so costly at this altitude.
Scorers - Monaghan: C McManus 1-2 (0-2fs), D Malone 1-1, R Beggan (0-1f, 0-1 45), D McKenna, T Kerr all 0-2 each, N McAdam 0-1.
Roscommon: F Cregg 0-5 (2fs), C Murtagh 1-2 (1-0 pen, 0-2fs), S Kilbride, E Smith 0-1 each.
Roscommon: D O'Malley; S McDermott, N Collins, N McInerney; D Murray, N Daly, R Stack; E Smith, I Kilbride; F Cregg, N Kilroy, C Devanney; C Murtagh, S Kilbride, C Cregg. Subs: C Conolly for Murtagh BC (34), U Harney for Kilbride (52), R Daly for Kilroy (63), C Shine for Devaney (67), J McManus for Cregg (69), C Shine for Devanney (67).
Monaghan: R Beggan; C Walshe, D Wylie, R Wylie; K Duffy, D Mone, F Kelly; N McAdam, K O'Connell; S Carey, D Malone, T Kerr; O Duffy, D Hughes, C McManus. Subs: C Boyle for R Wylie BC (28), D McKenna for Carey (52), B McGinn for O Duffy (59).