Monaghan produced an astonishing performance of intensity and class to capture their first Ulster title since 1988 to shock Jim McGuinness' All-Ireland champions Donegal in a 0-13 to 0-7 victory in Clones.
There were jubilant scenes as Monaghan fans streamed onto the pitch to celebrate a famous win that has shocked the world of gaelic games.
"It's magic. Absolutely magic. There is not a person in the country who thought we could do it," Monaghan's star forward Conor McManus said afterwards.
"We can take anyone on any given day."
Tommy Freeman added: "It's the best feeling in my life."
Monaghan's incredible rearguard action, midfield dominance with Darren Hughes in stirring form and virtuoso displays from Conor McManus and Kieran Hughes up front laid the foundation for a richly deserved triumph.
Donegal were a shadow of the team who lifted Sam Maguire last September with star men Colm McFadden and Michael Murphy completely out-of-sorts and the loss of Mark McHugh to a first-half injury was also pivotal.
It's only the second time Jim McGuinness has tasted defeat in the Championship and he will have to lift his players for a qualifier with Laois next weekend.
Conor Hughes gave the Farney men the ideal start with a fine run and point and goalie Rory Beggin scored with his first effort to double their advantage.
Monaghan had their tails up early and Conor McManus kicked a free he earned himelf and Padraig Donaghy kiced a superb score off the outside of the boot to give the underdogs a four-point lead after seven minutes.
A nasty clash of heads saw Mark McHugh and Stephen Gollogly depart the field.
Donegal had a Rory Kavanagh effort ruled out after linesman Cormac Reilly overruled the umpires decision to award a point after 20 minutes and Donegal were still scoreless.
Monaghan were defending with vigour and were continually frustrating Donegal who were missing chances.
Conor McManus' 28th minute free stretched the lead to five before Donegal finally opened their account in the 32nd minute through a Colm McFadden free.
Frank McGlynn came forward to kick the All-Ireland champions first score from play in injury time but they trailed by 0-5 to 0-2 at the break.
Monaghan could have a goal at the start but Kieran Hughes' effort was brilliantly cleared off the line by Ryan McHugh who replaced David Walsh at the break but Hughes recovered the ball to kick a point.
Ryan McHugh's impact was growing as he kicked a great score off the outside of his right boot to make it 0-6 to 0-3 after 43 minutes.
Another superb score from Kieran Hughes after great work from Dessie Mone and he added a third second half point moments later and Malachy O'Rourke's side led by five.
Colm McFadden pulled one back with a free but that was cancelled out by an incredible score from Dessie Mone.
Donegal needed a goal and Frank McGlynn almost provided it but his fisted effort went wide and then Michael Murphy produced a moment of class to take a long ball down one handed and get a shot away with his right but it trickled wide and Monaghan continued to lead with 13 minutes remaining by five points.
McFadden pulled a free back but it was cancelled out almost immediately by Conor McManus.
Donegal were resorting to long, high balls that the Monaghan defence dealt with admirably.
Rory Kavanagh pulled a point back in the 63rd minute but sub Chris McGuinness made an instant impact by turning sharply and pointing.
McFadden kicked a free with two minutes remaining before McGuinness forced a brilliant save from Paul Durcan with Rory Beggin drilling over the resultant 45.
It was extremely apt that the final point of the game went to one of Monaghan's greatest servants, Tommy Freeman, which added to an incredible occasion and a six-point victory.