Monaghan staged a storming finish to defeat Down 0-11 to 0-8 and book their place in the Ulster MFC final.
Conor McGrady hit two points to help Down lead by 0-5 to 0-4 at the break, but it was Monaghan who rose to the challenge in the second half.
They went in front for the first time with five minutes left thanks to a Ryan McAnespie point.
Monaghan took control with Conor McCarthy scoring a free and Dessie Ward sealing it in stoppage time.
Down started strongly and Donal McKeever and Daniel McCarthy both fired over, but they needed to defend solidly as Monaghan began to move with menace.
David McAllister and Fergal McGeough swept over Monaghan points, and but for some poor distribution, they could have got themselves in front.
McGrady's two points kept the Mourne lads ahead, but Conor McCarthy and Padraic Keenan both converted Monaghan frees to leave just a point between the sides at the interval.
Monaghan's late burst won it while midfielder David McAllister starred for the Farney team with three points.
Monaghan scorers: D McAllister 0-3, C McCarthy 0-2 (2f), P Keenan (f), R Wylie, J McElroy, F McGeough, R McAnespie, D Ward 0-1 each.
Down scorers: D McCarthy 0-3, C McGrady 0-2, D McKeever, J McDermott, R McAlinden (f) 0-1 each.