It was not the most handsome goal Brendan Devenney has ever scored but his long, dropping sky bomb that beat Armagh will be remembered in the north west for a lifetime. After over a decade of frustration, Donegal bested Armagh in the Ulster championship.

The scoreline of 1-9 to 1-8 holds the story of this Ulster rivalry - stingy, begrudging, close and exciting. Afterwards, the home players stood in the sunshine of MacCumhaill Park like dazed East Berliners marvelling at the rubble they had created and at their first glimpse of the promised West: an Ulster without Armagh.

"We got hit by a sucker punch. But I suppose if any team deserved to beat us, it was Donegal," said Big Joe Kernan afterwards, standing in the shadows.

To Donegal, Armagh was the big kid who took their lunch money year after year. Armagh demanded and they took. This was the day Donegal simply had to refuse. And yet as the teams marched around in the sunshine in front of an attendance of 19,780 the Armagh 15 looked even more brawny and more unbreakable. They shimmered with purpose.

And it was almost the same old story. Armagh are the Fianna Fáil of the Ulster scene. They reinvent themselves and find a way to win. The first 10 minutes was all about hard hitting and old scores, a nervous and at times spiteful affair. There was a point in it at half-time. Armagh then came out all business, fashioned a typically crafty goal finished by Oisín McConville and then began to play their compelling fast-slow football.

Maybe veteran Donegal players were waiting for the old Armagh sting - that brilliant, showboating finish inflicted upon them so many times. But it never came. Armagh were happy merely to hold on. And Donegal did not quit.

Adrian Sweeney, an old warhorse who must hate the colour orange, came in and kicked a great point in anger. They were still two points down and time running out. The game was still alive but Armagh had it. They possessed it. Devenney's high, booming kick looked last-ditch and harmless. Out of the corner of our eye, we saw Kevin Cassidy, the full-hearted Gweedore man barrelling into the square.

He rose with big Paul Hearty and then, unbelievably, the ball was in the net. In MacCumhaill Park, they were almost too stunned to cheer. It was like an apparition. Nobody could be sure who had scored it. "That was a cross," grinned Devenney afterwards but the goal was chalked next to his name.

Armagh were stoic and sporting and nagged by the fact that a few years back, they would not have coughed up this match. "I hope they win the Ulster title now," said Kernan. God knows, Armagh have enough of those. Donegal have faced down their bogeymen at long last.

Now, they must meet Tyrone for a place in the Ulster final. It is never easy up north.