Monaghan will discover their semi-final opponents next Sunday as Fermanagh face Antrim at Brewster Park, throw-in 16:00 BST.
There will be commentary on Radio Ulster medium wave with our live text coverage on the website.
The full match will be shown on BBC2 Northern Ireland at 19:00 BST.
See you next week.
Poll result
We asked who you thought would win the Ulster Championship - well, current holders Donegal topped the poll with 30% of the vote. Next came Armagh on 22%, Monaghan 12% and, would you believe, Fermanagh with 9%.
Thanks very much for taking part.
Antrim hurling woe
Antrim exit from the Leinster Hurling Championship after a 2-18 to 1-11 defeat by Carlow at Dr Cullen Park. Their only remaining hurling action this summer will be the Ulster final and it's the Christy Ring Cup for them next summer. Ouch.
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Maybe Cavan just lacked that wee bit of experience to get over the line. The game was there for them to win but fair play to Monaghan, they showed great character in the second half after not playing particularly well for much of the match."
Malachy O'Rourke's view
"In the second half, we just upped our game and that was the difference more than anything else. We were able to get Conor McManus on the ball a bit more.
"There was a time early in the second half when the game could have got away from us if our boys hadn't held their heads."
Celebrations
Monaghan are applauded by their delighted, and no doubt relieved, supporters. They now look forward to a semi-final against Fermanagh or Antrim on 21 June.
Full-time
Cavan 0-15 0-16 Monaghan
Colin Walshe's left foot sends over a nerve-settling score and Monaghan lead by two with less than a minute to go.
Martin Dunne lands a free for Cavan but seconds later the final whistle sounds and Monaghan go through - but only just.
Wide of the mark
InphoCopyright: Inpho
Raymond Galligan started in goal for Cavan instead of Conor GilsenanImage caption: Raymond Galligan started in goal for Cavan instead of Conor Gilsenan
Cavan's young keeper Raymond Galligan, who plays as a forward for his club, has a go from distance but the free goes wide.
The number 16 has another crack with a 45 - but it is wide again.
We are into added time.
Post update
Cavan 0-14 0-15 Monaghan
Cavan's number 14 makes it 14 points each. Martin Dunne landing over a fine score.
But Monaghan maestro Conor McManus quickly replies with a brilliant score.
Post update
Orla Bannon
BBC Sport at Breffni Park
That Hughes free puts Monaghan ahead for the first time since the 23rd minute.
On that occasion they stayed in front for only two minutes - can they hold on this time?
Join the debate at #bbcgaa
Niall: Why have Cabhan stopped releasing the ball into Argue...running into walls and negating the tactic that paid dividends.
Henky7: @bbcchampionship Who's going to win Ulster this year boys? With the Red Hands out of the way can Armagh do it this year Oisin?
Monaghan move into the lead thanks to a Kieran Hughes free. The last five scores have gone to the Farney county. Are Cavan letting their big opportunity slip?
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Cavan have panicked a bit but fair play to Monaghan for battling back. Cavan have lost their shape."
All level
Cavan 0-13 0-13 Monaghan
Monaghan equalise through a Dessie Mone free after Cavan's free-taker Martin Reilly receives a black card for hauling down an opponent.
Post update
Cavan 0-13 0-12 Monaghan
It is a one-point game now as veteran replacement Dick Clerkin registers from play. Cavan haven't scored for 10 minutes or so.
Having a Mone
Orla Bannon
BBC Sport at Breffni Park
Dessie Mone is still remonstrating with the umpire after not being given a penalty. He felt he was impeded as he tried to kick the ball.
Antrim Hurlers update
Antrim are heading out of the Leinster Hurling Championship and into next season's Christy Ring Cup as Carlow move 1-15 to 1-6 at Dr Cullen Park. Ciaran Johnston has also been sent off the Saffrons. Dark days for Antrim hurling.
Post update
Cavan 0-13 0-11 Monaghan
Conor McManus lands a free for Monaghan who felt they might have had a penalty just before that when Dessie Mone went down as Thomas Corr challenged. Would have been a harsh award.
Darren Hughes then charges forward to fire over another Monaghan point - deficit down to two now.
Cavan on top?
Cavan 0-13 0-9 Monaghan
Ciaran Brady is on target with a fine score from play and then Michael Argue's shot on the turn opens a four-point advantage for Cavan. Are Monaghan's hopes of a third successive Ulster final fading?
Cavan 0-11 0-9 Monaghan
Conor McManus does the business again with a free from the left - Monaghan really needed that!
Malone gets the road
Dermot Malone's afternoon comes to an early end as he gets a black card for a cynical bodycheck. So, he has to be replaced and Stephen Gollogly is the man summoned from the Monaghan bench.
Second half
Cavan 0-11 0-8 Monaghan
Two points from play in the opening minute - Karl O'Connell for Monaghan and Geroid McKernan with Cavan's reply.
Then Niall McDernott's free just makes it over the bar to put Cavan three points to the good.
Antrim hurlers update
Half-time: Carlow 0-8 1-3 Antrim. Carlow lead by two at the break at Dr Cullen Park even though they are down to 14 men after Marty Kavanagh's sending off.
Post update
Philip Jordan
Three-time All-Ireland winner
"Monaghan haven't been able to get a good supply into Conor McManus even though he looks to have the beating of his man."
Post update
Oisin McConville
BBC Sport NI GAA analyst
"I have no doubt the hairdryer will be out in the Monaghan dressing-room at half-time. Monaghan didn't look up for it in the first five minutes and it is very hard to lift it when you don't come out with the right attitude."
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Cavan are the more hungry team and they are getting more turnovers. Monaghan need to try and hit more long-range points in the second half."
Sideline shift
Orla Bannon
BBC Sport at Breffni Park
Cavan selector Anthony Forde is putting in as big a shift as the players. Manic running up and down the sideline and running on to issue a few instructions.
This game being played at an incredible speed. Can they keep this up for 70 minutes?
Post update
Cavan 0-9 0-7 Monaghan
Gearoid McKernan moves forward to slot over the last score of the first half with his trusty right boot. Underdogs Cavan enjoy a two-point advantage at the break.
Today's attendance: 18,540
Post update
Cavan 0-8 0-7 Monaghan
Cavan defender Ronan Flanagan advances to score a nice left-footed effort to edge the hosts into the lead.
Post update
Cavan 0-7 0-7 Monaghan
Cian Mackey goes forward and his right-foot effort is tipped over by the Monaghan keeper Rory Beggan for a point.
Play quickly switches to the other end and Paul Finlay adds to his free tally.
Keeper scores
Cavan 0-6 0-6 Monaghan
Cavan's young keeper Raymond Galligan lands a long-range free, Paul Finlay quickly replies for the visitors and Niall McDermott registers again to tie the game up once more.
Post update
Cavan 0-4 0-5 Monaghan
Conor McManus is accurate with another free and Monaghan have regained the lead. Star man McManus has four points already.
InphoCopyright: Inpho
Cavan should know all about the threat posed by Monaghan's Conor McManusImage caption: Cavan should know all about the threat posed by Monaghan's Conor McManus
Antrim hurlers update
Antrim are level 1-2 to 0-5 against Carlow in the Leinster Hurling Championship game at Dr Cullen Park which also started at 14:00. Conor Johnston has scored Antrim's goal.
Teams level
Cavan 0-4 0-4 Monaghan
Paul Finley is pushed just as he is about to shoot - Conor McManus slots over the resulting free and suddenly the sides are level
Yellow card
Cavan's Niall McDermott goes into the book for a high tackle.
It's close
Cavan 0-4 0-3 Monaghan
A foul on late replacement Shane Carey leads to Paul Finlay scoring Monaghan's second point with an easy free, and then Conor McManus scores from play to add to their tally.
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Terry Hyland will be very happy. He has got his tactics exactly right so far."
Post update
Cavan 0-4 0-1 Monaghan
Cavan extend their lead as Niall McDermott lands another free with his left peg
Monaghan keeper wide from long-range
Orla Bannon
BBC Sport at Breffni Park
Cavan fans giving Monaghan 'keeper Rory Beggan plenty of stick, especially after he misses his first long-range free attempt.
Switches all over the field - Michael Argue at full-forward for Cavan and having some battle with Drew Wylie.
Ronan Flanagan is wearing number four but playing at wing-forward!
Post update
Cavan 0-3 0-1 Monaghan
This is an encouraging start for Terry Hyland's Cavan. They go two points clear with another free, this one scored by Niall McDermott.
Post update
Martin McHugh
BBC Sport NI GAA analyst
"There is no fear in Cavan about Monaghan."
Post update
Cavan 0-2 0-1 Monaghan
Cavan move into the lead as Michael Argue fists over a point
Join the debate at #bbcgaa
Jarlath Burns: Very sensible points being made on @BBCSPORTNI The Championship re sledging.
No surprise that Malachy O'Rourke has made a couple of changes to his starting 15 - but no-one saw this one coming.
He's chosen the unknown Shane Carey to make his championship debut, replacing the veteran Dick Clerkin, in midfield.
Ryan McAnespie also comes into the attack in place of Owen Duffy.
Two changes for Cavan also - top scoring forward Martin Dunne is replaced by Niall Murray, no news on whether that's tactical or if Dunne has suffered an injury.
Raymond Galligan replaces Conor Gilsenan in goals.
Post update
In the Minor match, the Cavan boys beat their Monaghan counterparts by 2-17 to 1-8.
Twitter & Facebook
You can have your say on today's proceedings or send a question to our panel of pundits via Twitter by using #bbcgaa or going to our Facebook page
Team news
Monaghan have been boosted by the news that midfielder Darren Hughes is fit to play at Breffni Park today after recovering from a foot injury sustained in a club game.
Cavan defender Killian Clarke misses the big match because of a hamstring injury, but Cian Mackey is back in the Breffni line-up after missing the 2014 Championship.
Get Involved
Monaghan were favourites to win the Ulster before the competition started, and they certainly are on the easier looking side of the draw.
However, Donegal now have the slightly shorter odds with the bookmakers after seeing off Mickey Harte's Tyrone in last week's preliminary round.
But who do you think will be crowned provincial champions on 19 July?
You can choose your winners by using the voting buttons. The Ts and Cs can be found here.
The vote will close at 15:30 BST and we will let you know the result.
Starting soon
Press EyeCopyright: Press Eye
Cavan are underdogs with Monaghan boasting a better recent record in the ChampionshipImage caption: Cavan are underdogs with Monaghan boasting a better recent record in the Championship
Welcome to our live text coverage of the first quarter-final in the 2015 Ulster Senior Football Championship.
It's a neighbourly dispute today as Monaghan travel to Breffni Park to take on deadly rivals Cavan.
A glance at the record book tells you that Cavan are by far and away the most successful county in the history of the Ulster Championship.
However, they have not lifted the Anglo-Celt Cup for 18 years and it is Monaghan who have the most recent pedigree, having won in 2013 and appearing in last year's final.
Indeed, Division One semi-finalists Monaghan are favourites to progress to a semi-final date with unfancied Fermanagh or the even more unfancied Antrim.
Live Reporting
Lyle Jackson
All times stated are UK
InphoCopyright: Inpho Raymond Galligan started in goal for Cavan instead of Conor GilsenanImage caption: Raymond Galligan started in goal for Cavan instead of Conor Gilsenan 
InphoCopyright: Inpho Cavan should know all about the threat posed by Monaghan's Conor McManusImage caption: Cavan should know all about the threat posed by Monaghan's Conor McManus 
Press EyeCopyright: Press Eye Cavan are underdogs with Monaghan boasting a better recent record in the ChampionshipImage caption: Cavan are underdogs with Monaghan boasting a better recent record in the Championship
Latest PostComing up next
Monaghan will discover their semi-final opponents next Sunday as Fermanagh face Antrim at Brewster Park, throw-in 16:00 BST.
There will be commentary on Radio Ulster medium wave with our live text coverage on the website.
The full match will be shown on BBC2 Northern Ireland at 19:00 BST.
See you next week.
Poll result
We asked who you thought would win the Ulster Championship - well, current holders Donegal topped the poll with 30% of the vote. Next came Armagh on 22%, Monaghan 12% and, would you believe, Fermanagh with 9%.
Thanks very much for taking part.
Antrim hurling woe
Antrim exit from the Leinster Hurling Championship after a 2-18 to 1-11 defeat by Carlow at Dr Cullen Park. Their only remaining hurling action this summer will be the Ulster final and it's the Christy Ring Cup for them next summer. Ouch.
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Maybe Cavan just lacked that wee bit of experience to get over the line. The game was there for them to win but fair play to Monaghan, they showed great character in the second half after not playing particularly well for much of the match."
Malachy O'Rourke's view
"In the second half, we just upped our game and that was the difference more than anything else. We were able to get Conor McManus on the ball a bit more.
"There was a time early in the second half when the game could have got away from us if our boys hadn't held their heads."
Celebrations
Monaghan are applauded by their delighted, and no doubt relieved, supporters. They now look forward to a semi-final against Fermanagh or Antrim on 21 June.
Full-time
Cavan 0-15 0-16 Monaghan
Colin Walshe's left foot sends over a nerve-settling score and Monaghan lead by two with less than a minute to go.
Martin Dunne lands a free for Cavan but seconds later the final whistle sounds and Monaghan go through - but only just.
Wide of the mark
Cavan's young keeper Raymond Galligan, who plays as a forward for his club, has a go from distance but the free goes wide.
The number 16 has another crack with a 45 - but it is wide again.
We are into added time.
Post update
Cavan 0-14 0-15 Monaghan
Cavan's number 14 makes it 14 points each. Martin Dunne landing over a fine score.
But Monaghan maestro Conor McManus quickly replies with a brilliant score.
Post update
Orla Bannon
BBC Sport at Breffni Park
That Hughes free puts Monaghan ahead for the first time since the 23rd minute.
On that occasion they stayed in front for only two minutes - can they hold on this time?
Join the debate at #bbcgaa
Niall: Why have Cabhan stopped releasing the ball into Argue...running into walls and negating the tactic that paid dividends.
Henky7: @bbcchampionship Who's going to win Ulster this year boys? With the Red Hands out of the way can Armagh do it this year Oisin?
You can get in touch at #bbcgaa or pop on to the BBC Championship Facebook page
Monaghan momentum
Cavan 0-13 0-14 Monaghan
Monaghan move into the lead thanks to a Kieran Hughes free. The last five scores have gone to the Farney county. Are Cavan letting their big opportunity slip?
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Cavan have panicked a bit but fair play to Monaghan for battling back. Cavan have lost their shape."
All level
Cavan 0-13 0-13 Monaghan
Monaghan equalise through a Dessie Mone free after Cavan's free-taker Martin Reilly receives a black card for hauling down an opponent.
Post update
Cavan 0-13 0-12 Monaghan
It is a one-point game now as veteran replacement Dick Clerkin registers from play. Cavan haven't scored for 10 minutes or so.
Having a Mone
Orla Bannon
BBC Sport at Breffni Park
Dessie Mone is still remonstrating with the umpire after not being given a penalty. He felt he was impeded as he tried to kick the ball.
Antrim Hurlers update
Antrim are heading out of the Leinster Hurling Championship and into next season's Christy Ring Cup as Carlow move 1-15 to 1-6 at Dr Cullen Park. Ciaran Johnston has also been sent off the Saffrons. Dark days for Antrim hurling.
Post update
Cavan 0-13 0-11 Monaghan
Conor McManus lands a free for Monaghan who felt they might have had a penalty just before that when Dessie Mone went down as Thomas Corr challenged. Would have been a harsh award.
Darren Hughes then charges forward to fire over another Monaghan point - deficit down to two now.
Cavan on top?
Cavan 0-13 0-9 Monaghan
Ciaran Brady is on target with a fine score from play and then Michael Argue's shot on the turn opens a four-point advantage for Cavan. Are Monaghan's hopes of a third successive Ulster final fading?
Cavan 0-11 0-9 Monaghan
Conor McManus does the business again with a free from the left - Monaghan really needed that!
Malone gets the road
Dermot Malone's afternoon comes to an early end as he gets a black card for a cynical bodycheck. So, he has to be replaced and Stephen Gollogly is the man summoned from the Monaghan bench.
Second half
Cavan 0-11 0-8 Monaghan
Two points from play in the opening minute - Karl O'Connell for Monaghan and Geroid McKernan with Cavan's reply.
Then Niall McDernott's free just makes it over the bar to put Cavan three points to the good.
Antrim hurlers update
Half-time: Carlow 0-8 1-3 Antrim. Carlow lead by two at the break at Dr Cullen Park even though they are down to 14 men after Marty Kavanagh's sending off.
Post update
Philip Jordan
Three-time All-Ireland winner
"Monaghan haven't been able to get a good supply into Conor McManus even though he looks to have the beating of his man."
Post update
Oisin McConville
BBC Sport NI GAA analyst
"I have no doubt the hairdryer will be out in the Monaghan dressing-room at half-time. Monaghan didn't look up for it in the first five minutes and it is very hard to lift it when you don't come out with the right attitude."
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Cavan are the more hungry team and they are getting more turnovers. Monaghan need to try and hit more long-range points in the second half."
Sideline shift
Orla Bannon
BBC Sport at Breffni Park
Cavan selector Anthony Forde is putting in as big a shift as the players. Manic running up and down the sideline and running on to issue a few instructions.
This game being played at an incredible speed. Can they keep this up for 70 minutes?
Post update
Cavan 0-9 0-7 Monaghan
Gearoid McKernan moves forward to slot over the last score of the first half with his trusty right boot. Underdogs Cavan enjoy a two-point advantage at the break.
Today's attendance: 18,540
Post update
Cavan 0-8 0-7 Monaghan
Cavan defender Ronan Flanagan advances to score a nice left-footed effort to edge the hosts into the lead.
Post update
Cavan 0-7 0-7 Monaghan
Cian Mackey goes forward and his right-foot effort is tipped over by the Monaghan keeper Rory Beggan for a point.
Play quickly switches to the other end and Paul Finlay adds to his free tally.
Keeper scores
Cavan 0-6 0-6 Monaghan
Cavan's young keeper Raymond Galligan lands a long-range free, Paul Finlay quickly replies for the visitors and Niall McDermott registers again to tie the game up once more.
Post update
Cavan 0-4 0-5 Monaghan
Conor McManus is accurate with another free and Monaghan have regained the lead. Star man McManus has four points already.
Antrim hurlers update
Antrim are level 1-2 to 0-5 against Carlow in the Leinster Hurling Championship game at Dr Cullen Park which also started at 14:00. Conor Johnston has scored Antrim's goal.
Teams level
Cavan 0-4 0-4 Monaghan
Paul Finley is pushed just as he is about to shoot - Conor McManus slots over the resulting free and suddenly the sides are level
Yellow card
Cavan's Niall McDermott goes into the book for a high tackle.
It's close
Cavan 0-4 0-3 Monaghan
A foul on late replacement Shane Carey leads to Paul Finlay scoring Monaghan's second point with an easy free, and then Conor McManus scores from play to add to their tally.
Post update
Martin McHugh
BBC Sport NI GAA analyst
"Terry Hyland will be very happy. He has got his tactics exactly right so far."
Post update
Cavan 0-4 0-1 Monaghan
Cavan extend their lead as Niall McDermott lands another free with his left peg
Monaghan keeper wide from long-range
Orla Bannon
BBC Sport at Breffni Park
Cavan fans giving Monaghan 'keeper Rory Beggan plenty of stick, especially after he misses his first long-range free attempt.
Switches all over the field - Michael Argue at full-forward for Cavan and having some battle with Drew Wylie.
Ronan Flanagan is wearing number four but playing at wing-forward!
Post update
Cavan 0-3 0-1 Monaghan
This is an encouraging start for Terry Hyland's Cavan. They go two points clear with another free, this one scored by Niall McDermott.
Post update
Martin McHugh
BBC Sport NI GAA analyst
"There is no fear in Cavan about Monaghan."
Post update
Cavan 0-2 0-1 Monaghan
Cavan move into the lead as Michael Argue fists over a point
Join the debate at #bbcgaa
Jarlath Burns: Very sensible points being made on @BBCSPORTNI The Championship re sledging.
You can get in touch at #bbcgaa or pop on to the BBC Championship Facebook page
All square
Cavan 0-1 0-1 Monaghan
Cavan pull level through a straightforward free by Cian Mackey although Martin Reilly is wide of the mark with a chance to put the Breffni men ahead.
Studio debate on sledging
Philip Jordan
Three-time All-Ireland winner
"I was too busy trying to keep up with Oisin on the football field to have any time for sledging him."
Cavan 0-0 0-1 Monaghan
Conor McManus lands a free to give Monaghan the lead after just 55 seconds
Throw-in
Match starts with Monaghan surging forward
Join the debate at #bbcgaa
Christopher Potter: Think a draw or a point win either way. Certainly playing at home a big help to Cavan
Brady: The abuse won't change because it's win at all costs now more than ever.
Lisa McNulty: What an inspiration Oisín McConville is. We know his story and my goodness hasn't he turned his life around.
You can get in touch at #bbcgaa or pop on to the BBC Championship Facebook page.
Late team changes
Orla Bannon
BBC Sport at Breffni Park
No surprise that Malachy O'Rourke has made a couple of changes to his starting 15 - but no-one saw this one coming.
He's chosen the unknown Shane Carey to make his championship debut, replacing the veteran Dick Clerkin, in midfield.
Ryan McAnespie also comes into the attack in place of Owen Duffy.
Two changes for Cavan also - top scoring forward Martin Dunne is replaced by Niall Murray, no news on whether that's tactical or if Dunne has suffered an injury.
Raymond Galligan replaces Conor Gilsenan in goals.
Post update
In the Minor match, the Cavan boys beat their Monaghan counterparts by 2-17 to 1-8.
Twitter & Facebook
You can have your say on today's proceedings or send a question to our panel of pundits via Twitter by using #bbcgaa or going to our Facebook page
Team news
Monaghan have been boosted by the news that midfielder Darren Hughes is fit to play at Breffni Park today after recovering from a foot injury sustained in a club game.
Cavan defender Killian Clarke misses the big match because of a hamstring injury, but Cian Mackey is back in the Breffni line-up after missing the 2014 Championship.
Get Involved
Monaghan were favourites to win the Ulster before the competition started, and they certainly are on the easier looking side of the draw.
However, Donegal now have the slightly shorter odds with the bookmakers after seeing off Mickey Harte's Tyrone in last week's preliminary round.
But who do you think will be crowned provincial champions on 19 July?
You can choose your winners by using the voting buttons. The Ts and Cs can be found here.
The vote will close at 15:30 BST and we will let you know the result.
Starting soon
Welcome to our live text coverage of the first quarter-final in the 2015 Ulster Senior Football Championship.
It's a neighbourly dispute today as Monaghan travel to Breffni Park to take on deadly rivals Cavan.
A glance at the record book tells you that Cavan are by far and away the most successful county in the history of the Ulster Championship.
However, they have not lifted the Anglo-Celt Cup for 18 years and it is Monaghan who have the most recent pedigree, having won in 2013 and appearing in last year's final.
Indeed, Division One semi-finalists Monaghan are favourites to progress to a semi-final date with unfancied Fermanagh or the even more unfancied Antrim.