Summary
FT: Down 2-6 Armagh 0-13
Armagh will meet Donegal or Tyrone in the final.
Donegal v Tyrone semi-final is on Sunday 28 April, 14:00 BST.
The Ulster final in on Sunday 12 May.
Live Reporting
Niall Keenan
Final whistlepublished at 19:14 27 April
19:14 27 April
Down 2-6 Armagh 0-13
Down didn't make things easy for Armagh but in the end Kieran McGeeney's men waited for the right moment in added-on time as Jason Duffy rose to the occasion and split the sticks.
You can read Orla Bannon's report from the game here.
We will be back tomorrow to find out who Armagh's opponents in the final will be as Donegal and Tyrone face off at Celtic Park.
We hope to see you then, but for now, goodnight.
Donegal face Tyrone in second semi-finalpublished at 19:08 27 April
19:08 27 April
Donegal v Tyrone Sunday (14:00 BST)
Armagh will meet the winners of the second semi-final between Donegal and Tyrone, with those sides meeting at Celtic Park on Sunday.
The game will be live on the BBC iPlayer and BBC Sport website.
Full-timepublished at 18:59 27 April
18:59 27 April
Down 2-6 Armagh 0-13
Duffy does it for Armagh. They will play again in the Ulster Final this year.
Postpublished at 18:57 27 April
18:57 27 April
Down 2-6 Armagh 0-13
Oisin Savage fires wide with an audacious free from the sideline. That could be it.
Postpublished at 18:55 27 April
18:55 27 April
Down 2-6 Armagh 0-13
Is that the winner? Jason Duffy steps up for Armagh to kick them ahead. One minute of stoppage time to go.
Postpublished at 18:50 27 April
18:50 27 April
Down 2-6 Armagh 0-12
Level once more. Cool as you like from Armagh substitute Aidan Nugent as he delicately curls the ball from the right-hand side and over the bar. Tension is palpable as we approach the end of regular time.
Huge final tenpublished at 18:42 27 April
18:42 27 April
Down 2-6 Armagh 0-10
Michael Murphy
Former Donegal captain and All-Ireland winner on GAAGoThis is a huge final ten minutes for Down. Not just to get into an Ulster Final but into the All-Ireland series, it's absolutely massive.
Postpublished at 18:40 27 April
18:40 27 April
Down 2-6 Armagh 0-10
Pat Havern taps over a free for Down after Jason Duffy appeared to be harshly penalised for touching the ball on the ground. This wasn't in the script. Down lead by two with just over ten minutes of normal time remaining.
Armagh looking nervypublished at 18:37 27 April
18:37 27 April
Down 2-5 Armagh 0-10
John Haughey
BBC Sport NI at ClonesEverything looked set fair for Armagh to reach this Ulster Final with the way the draw fell but they are looking decidedly nervy out there at the moment after that second Down goal.
The Mournemen are running directly at the Armagh defence when they have the ball and Kieran McGeeney's side are looking somewhat directionless at the moment. Still time for them to change matters obviously.
Postpublished at 18:36 27 April
18:36 27 April
Down 2-5 Armagh 0-10
Jason Duffy draws the foul and Rory Grugan is on hand once again to stroke over the resulting free.
Postpublished at 18:34 27 April
18:34 27 April
Down 2-5 Armagh 0-9
A sensational score from Ryan Johnston off the outside of his right boot to give Down a two-point lead.
Postpublished at 18:32 27 April
18:32 27 April
Down 2-4 Armagh 0-9
Rory Grugan converts his fourth free of the game.
GOAL!published at 18:30 27 April
18:30 27 April
Down 2-4 Armagh 0-8
Down find the net again. The ball comes out to Ryan Magill, he stabs it goalwards and it deflects over the line. Scrappy? Yes, but Down won't care.
Postpublished at 18:28 27 April
18:28 27 April
Down 1-4 Armagh 0-8
Much more open at the start of the second period. Armagh take the lead again with another routine Rory Grugan free.
Postpublished at 18:26 27 April
18:26 27 April
Down 1-4 Armagh 0-7
Sides level for the third time. Daniel Guinness and half-time substitute Danny Magill split the sticks as Down weather that early Armagh storm.
Postpublished at 18:23 27 April
18:23 27 April
Down 1-2 Armagh 0-7
Last season's Ulster finalists have come flying out of the traps at the start of this second half. There has been a fire lit under Rian O'Neill at half-time it seems as he doubles Armagh's lead.
Postpublished at 18:19 27 April
18:19 27 April
Down 1-2 Armagh 0-6
Rian O'Neill fetches the throw-up and tears down the field drawing a free which Rory Grugan easily dispatches.
Postpublished at 18:17 27 April
18:17 27 April
Down 1-2 Armagh 0-5
Liam Devenney throws the ball in to resume the action.Which way is this going to swing?
GAA Social with Liam Hinpheypublished at 18:16 27 April
18:16 27 April
HT: Down 1-2 Armagh 0-5
On this week's GAA Social, former Derry footballer and hurler Liam Hinphey joins Thomas and Oisin to talk about life on and off the pitch.
Listen to the GAA Social here.
Getting hot and heavypublished at 18:06 27 April
18:06 27 April
HT: Down 1-2 Armagh 0-5
John Haughey
BBC Sport NI at ClonesI begged for a game to break out after 25 minutes and it has following Ceilum Doherty's goal.
Liam Devenney's refereeing is raising a few hackles among both sets of supporters it must be said.
Down great Sean O'Neill just walked by the press box a second ago letting us know his thoughts.
Immediately after the half-time whistle, Kieran McGeeney strode in Devenney's direction and that led his opposite number Conor Laverty to also get involved in the verbal exchanges.
In addition, Armagh selector Kieran Donaghy registered a protest with one of the linesmen but thankfully the players made their way to the dressing-rooms without any disturbances which isn't always the case these days.