A pointed mark from Paul Cassidy has the Oak Leaf County two to-the-good.

It's all Derry so far, and Donegal have hardly had any possession of the ball.

Ethan Doherty is the first player on the scoreboard, and he has Derry ahead early on.

The ball is thrown in and the game is underway at Celtic Park!

Note: Ciaran Thompson is wearing number 32 as opposed to number 8 as listed in the programme.

Oisin McConville
Armagh All-Ireland winner on BBC Sport

It does feel a bit different from the challenge matches that we've had so far. There's a real vibrancy around the ground and I've been looking forward to it. Hopefully the two teams can deliver.

Matt Gault
BBC Sport NI at Celtic Park

There's so much anticipation around seeing how Donegal will approach the Derry kick-out.

In addition to being one of the most effective keepers at coming up the field and joining the play, Odhran Lynch's kick-outs have been crucial to Derry building their attacks.

If McGuinness has surmised a way to rattle the Oak Leafers, it could be key for Donegal, with Shaun Patton's rocket of a boot at the other end likely to be a key outlet for the green and gold.

When I spoke to Michael Murphy earlier in the week, he was fascinated to see how the bigger lads in the Donegal would match up against Derry's physicality in the middle, in particular Conor Glass.

Donegal have named Ciaran Thompson and Michael Langan to start in midfield. They're both at least 6ft 2in, so that should prove a fascinating battle.

Michael Murphy
Former Donegal captain and All-Ireland winner on BBC Sport

It's a brilliant one - the venue is packed and it's fingers crossed for a Donegal victory.

These sides last met in January as Derry claimed their 13th McKenna Cup success following a 0-12 to 0-6 win at a blustery Healy Park in Omagh.

It was largely a forgettable final with both managers keeping their powder dry ahead of today's Ulster championship tussle.

Both sides were left to count the cost of an on-field scuffle on 52 minutes. Derry's Brendan Rogers and Donegal captain Patrick McBrearty were issued with straight red-cards.

Read more here

A stoppage-time point from Aaron Doherty helped Donegal to a 0-15 to 0-14 victory over Armagh in the Division Two final at Croke Park last month.

A tight first half ended with Donegal edging it 0-8 to 0-7. Donegal pulled away at the beginning of the second half but Armagh fought back to take a late lead in Dublin.

But it was Donegal who had the final say as they scored three of the last four points with Doherty popping up with the last-gasp winner.

Read more here

Image source, Inpho

Derry beat Dublin in a penalty shootout after a dramatic Division One decider ended in a 3-18 to 2-21 draw at Croke Park on Sunday.

Colm Basquel netted for Dublin as the teams went in level at the break. Shane McGuigan and Eoin McEvoy goals saw Derry move in front but Dublin hit back to take the game to extra-time.

McEvoy struck again and Derry won the shootout 3-1 after Greg McEneaney's last-gasp goal saw a dramatic final go to penalties.

Read more here

Image source, Inpho

Donegal All-Ireland winning captain Michael Murphy believes Derry might just edge affairs at Celtic Park.

'My heart will always tell me that Donegal can win, and while Jim's positive influence has strengthened my belief in this Donegal team, I can't get past the idea that getting to the very top requires a timeframe.

Donegal are only seven months into this journey. Last year, not only did they lose a lot of games, but they also lost some of that physicality that you get from playing the best teams in the country.

Derry are in a different position. This group have built cohesion, conditioning and a winning formula over the past five years. They've had big wins in Ulster finals and crushing defeats in All-Ireland semi-finals.

They have been through a lot together and it's hard to look past that going into Saturday.'

Read more of Michael Murphy's column here

Image source, Inpho

Mickey Harte says his Derry side must shoulder the pressure of being the "hunted" as they prepare to lock horns this evening.

After winning the Division One title, Derry are aiming to complete a hat-trick of Ulster titles but Harte admits Donegal are a "different proposition" under Jim McGuinness.

"We've seen what he's done the last time he was in [as Donegal boss], Harte said of McGuinness.

"He organises and motivates people very well. He's a very astute manager and he has quality players there, players who were successful at underage and have matured into young Gaelic football athletes of the highest standard.

Read more here

Image source, Inpho

Matt Gault
BBC Sport NI at Celtic Park

It really feels like the Ulster Championship now.

Just took a wee dander around Celtic Park there and it's filling up rightly.

The colour, the sunshine, the countless fans buzzing about the place. You couldn't ask for a better day for a big championship match.

Hopefully the football lives up to it.

Image source, BBC Sport

Image source, BBC Sport

For Mickey Harte it's a case of 'if it's not broken, don't fix it' as Derry line out with the same starting 15 who defeated Dublin in the Division One league final three weeks ago.

Donegal make several changes to the side who triumphed over Armagh in the Division Two final on the same day, with key players Daire O Baoil and Ryan McHugh returning, however Paddy McBrearty who was listed to start has dropped out of the team half an hour from throw-in.

O Baoil is in for Caolan McColgan and McHugh is in for Kevin McGettigan. Jason McGee (wearing number 27) replaces McBrearty and Brendan McCole is in for Odhran Doherty.

Derry: O Lynch; C McCluskey, C McKaigue, D Baker; C Doherty, E McEvoy, P McGrogan; C Glass, B Rogers; E Doherty, C McFaul, P Cassidy; N Loughlin, S McGuigan, L Murray.

Donegal: S Patton; M Curran, C Moore, P Mogan; R McHugh, C McGonagle, S O'Donnell; C Thompson, M Langan; B McCole, N O'Donnell, D O Baoil; J McGee, O Gallen, A Doherty.

Image source, Inpho

Matt Gault
BBC Sport NI at Celtic Park

Jim McGuinness had a few sleepless nights thinking about facing Mickey Harte's Tyrone during his first spell with Donegal.

It seems likely he's had a similar experience over the past six months since discovering he was to meet his old foe again.

When McGuinness took over at Donegal in 2011, Harte's Red Hands were two-in-a-row Ulster champions. Thirteen years on, Harte is again attempting to guide a team to a provincial hat-trick.

The difference, of course, is it's Derry, not his beloved Tyrone, he's leading.

Harte and McGuinness' three Ulster encounters between 2011 and 2013 were all won by the Donegal man.

In order to get a fourth, many feel he'll require all his tactical nous and motivational skills to stop a Derry side widely regarded as genuine All-Ireland contenders.

It's beautifully set up.

Last weekend's Ulster SFC action was lacklustre fare and if Mickey Harte's renewal of rivalries with Jim McGuinness doesn't kickstart the provincial series into life nothing will.

Harte's shock arrival to the Derry job last September immediately had GAA folks salivating at the prospect of him battling once again with the Donegal footballing messiah, who himself had been cajoled into re-taking the reins in his native county following their annus horribilis in 2023.

The back to the future references to those Harte-McGuinness Ulster tussles from 2011-13, when all three were won by the Glenties man, had to be neatly rounded off by three-in-a-row seeking Derry being drawn against Donegal in their Ulster opener. It was written in the stars.

Read more of John Haughey's preview here

Image source, Inpho

It's the game everyone was talking about when the Ulster SFC draw was made with a mouth-watering showdown between the Oak Leafers and Donegal in the quarter-finals.

People have been counting the days down to this one - it's finally here so let battle commence!

These are two teams on the up with Derry starting favourites on home turf as they chase a third straight Anglo-Celt Cup triumph.

They showed their pedigree three weeks ago by clinching the Division One title after a thrilling victory over All-Ireland champions Dublin.

Donegal are also league champions, winning promotion straight back to the top flight before beating Armagh in the Division Two final.

Then there's the All-Ireland SFC royalty on the sidelines - Derry boss Mickey Harte was a three-time winner with Tyrone while Jim McGuinness guided Donegal to Sam Maguire Cup glory in 2012 during his first stint in charge.

It's been a largely uninspiring Ulster SFC so far but this promises to be an absolute cracker and you can watch it all unfold here.

Thanks for joining us.

Image source, Inpho