There will be no Leinster team in Division 1 next season.
A late Jack McCarron free in injury time sealed a dramatic win for Monaghan and in the process relegated Dublin and Kildare.
County Farney extended their stay in the top flight to nine years, while Dublin finished in the National League Division One relegation zone for the first time since 1995.
Meanwhile, Mayo booked a Division 1 final date with Kerry, beating Kildare 2-20 to 0-18 at Carrick-on-Shannon.
Elsewhere, Tyrone and Donegal took care of business to avoid the drop, with victories over Kerry and Armagh respectively.
The four deciders of the NFL will take place in Croke Park next weekend. Cavan vs Tipperary (2.30pm) and Louth vs Limerick (4.45pm) will take place on Saturday. Roscommon vs Galway (1.45pm) and Kerry vs Mayo (4pm) will take place on Sunday.
Monaghan 3-13 Dublin 1-18
Donegal 1-14 Armagh 1-13
Kerry 1-15 Tyrone 2-11
Mayo 2-20 Kildare 0-18
NFL Division 1 Table
Monaghan 3-13 Dublin 1-18
McCarron’s late winner sealed the Dubs’ dramatic relegation, in a contest that has had its ups and downs.
Dublin got off to a good start, with marks from Cormac Costello and Seán Bugler helping them lead 0-4 to 0-1.
However, Farney County then took control. An 11th-minute goal from Sean Jones helped turn the tide, with the hosts going 1-4 unanswered.
Leading 1-7 to 0-5, Seamus ‘Banty’ McEnaney’s side seemed in control. But champions Leinster scored the last three of the first half to close the gap to just two points.
Farney County got off to a dream start in the second half. Gary Mohan was down for a penalty and Jack McCarron sent him off.
Nonetheless, Dublin dug deep and the tide seemed to turn in the 52nd minute when Ryan Wylie was sent off after a second yellow card. Seconds later, Dean Rock made it a three-point game.
However, Jack McCarron stretched the hosts’ advantage with an audacious lob over Michael Shiel which fell into the net.
Dublin’s numerical advantage was short-lived, as James McCarthy also received his marching orders.
Nevertheless, the capital team hung on and remarkably equalized thanks to a penalty from Dean Rock in added time.
Amid results elsewhere, a draw was not going to be enough for either side. And it was Farney County that snatched it, with McCarron holding back his temper from a free delay.
monaghan: Rory Beggan; Drew Wylie, Conor Boyle (0-1), Ryan Wylie; Ryan McAnespie, Dessie Ward, Niall Kearns; Darren Hughes (0-1), Kieran Hughes (0-2); Conor McCarthy; Fintan Kelly, Shane Carey (0-2, 0-1f); Jack McCarron (2-5, 1-0p, 0-2f), Gary Mohan (0-1, 0-1f), Sean Jones (1-0).
Subs: Colin Walshe for Sean Jones (ht), Andrew Woods for Shane Carey (ht), Karl O’Connell for Fintan Kelly (45), Killian Lavelle for Darren Hughes (65), Kieran Duffy for Kieran Hughes (69), Conor McManus for Colin Walshe (74).
Dublin: Michael Shiel; Michael Fitzsimons, David Byrne, Eoin Murchan; James McCarthy, Jonny Cooper, Robert McDaid; Brian Fenton, Tom Lahiff; Brian Howard (0-1), Seán Bugler (0-2, 0-1m), Niall Scully; Cormac Costello (0-4, 0-1m), Ciarán Kilkenny, Dean Rock (1-9, 0-8f, 1-0p).
Subs: Lee Gannon (0-2) for Tom Lahiff (23), Cian Murphy for Robert McDaid (30), Brian O’Leary for Niall Scully (58), Lorcan O’Dell for Cormac Costello (65), Alex Wright for Brian O’Leary (70).
In the second tier, Roscommon defeated Galway 1-20 to 1-15 to join the Tribesmen in the next tier for 2023.
Cork beat Offaly 1-21 to 1-20, to condemn Faithful County to relegation.
The other two draws proved inconsequential, as Derry beat Meath 1-16 to 2-11 at Navan, while Clare overcame Down, 2-14 to 1-9.
NFL Division 2 Table
Mickey Harte’s Louth team confirmed their promotion with a 2-17 to 1-13 win over Wicklow, and in the process relegated Garden County.
Limerick will join County Wee in the second tier next season, after Billy Lee’s charges beat Fermanagh, 1-16 to 0-14. The treaty win made Westmeath’s 1-13 0-12 victory over Antrim largely irrelevant.
At the other end of the table, Longford saw Laois in a de facto relegation play-off, 2-17 to 1-13.
NFL Division 3 Table