Louth make the perfect start to the second half.

Sam Mulroy picks out James Maguire, who opens the scoring inside the opening minute to stretch the Wee County's advantage.

It gets even better moments later as Louth win the resulting kick-out and Kieran McArdle curls over an excellent point for his first score of the afternoon.

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We're back under way at Croke Park, with 35 minutes separating Louth or Monaghan from a place in the All-Ireland semi-finals.

John McGovern
BBC Sport NI contributor

Both managers have plenty to think about after a breathless opening half.

Gavin Devlin will be delighted with how Louth have responded to Sean Callaghan's early red card, overturning a deficit to lead by two at the break thanks to Ciaran Downey's stunning late score.

Gabriel Bannigan, meanwhile, will feel Monaghan are still well placed despite trailing. The Farney men have coped admirably with the late withdrawals of Rory Beggan and Karl Gallagher, with replacement goalkeeper Jamie Mooney and goalscorer Oisin McGorman both making telling contributions.

With Monaghan holding a numerical advantage for the entire second half, there is still plenty to play for at Croke Park.

The joy was etched across Oisin McGorman's face after scoring Monaghan's goal.

But it's Louth who lead at the break!

No shortage of talking points. This one is finely poised.

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What a finish to the opening half.

Ciaran Downey drills over a spectacular point from outside the 45 to hand the Wee County a two-point lead with the final kick before the hooter.

Despite losing Sean Callaghan to a sixth-minute red card, Louth have produced a remarkable response and head into the interval in front at Croke Park.

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Monaghan look happy to slow the tempo as half-time approaches, but Conor McCarthy is penalised for overcarrying to hand Louth a chance to break.

Craig Lennon skips away brilliantly before sending a dangerous ball into the square. It drops short and momentarily spills from goalkeeper Jamie Mooney's grasp, but Monaghan recover before Louth can capitalise.

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Louth are back on level terms despite playing with 14 men.

Sam Mulroy converts another free to take his tally to four points before James Maguire follows up moments later with the equaliser.

An impressive response from the Wee County, with five minutes remaining in the opening half.

Ryan Burns thinks he has landed a two-pointer as he races towards the arc, but his effort has come from just inside the line.

It's a point rather than two, reducing Monaghan's lead back to two.

Monaghan threaten another goal moments later.

Oisin McGorman almost turns provider as he picks out Andrew Woods, but Niall McDonnell sticks out a crucial leg to divert the danger.

The attack stays alive, however, and Ryan Wylie arrives to split the posts, restoring Monaghan's three-point advantage.

Ryan Wylie is penalised for a foul on Kieran McArdle, who requires treatment before leaving the field as a blood substitution. Ciaran Byrne is introduced in his place.

Sam Mulroy steps up to the resulting free and calmly converts to cut Monaghan's lead to two.

Oisin McGorman finds himself in space once again, but this time he can't add to his tally as his effort drifts wide of the posts.

Monaghan remain three points in front with 10 minutes left to play in the opening half.

Chances go begging at both ends.

Ciaran Downey pulls his effort wide for Louth after Monaghan also fail to make the most of a promising attack.

It's now three wides for the Farney men and four for the Wee County.

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Monaghan strike for the first major of the afternoon.

Stephen O'Hanlon bursts into the Louth square before unselfishly fisting the ball to late replacement Oisin McGorman, who sells a clever dummy at the left post before blasting to the net.

The Farney men open up some daylight after 20 minutes at Croke Park.

Sam Mulroy is made to work for the opening before showing great patience in possession.

The Louth captain creates just enough space inside the arc and curls over a fine score to bring the sides level once again at Croke Park.

Conor McCarthy's effort drifts wide, but play is brought back for a Monaghan free.

Micheál Bannigan makes no mistake from the placed ball to edge the Farney men back in front after 18 minutes.

Odhran Crumley
BBC Sport NI at Croke Park

Louth could have folded after that red card for Sean Callaghan, but they responded by rattling off the next four scores.

They could have had a goal only for Jamie Mooney's remarkable save from Craig Lennon's effort.

There's plenty of life in Gavin Devlin's side yet.

Ryan Burns shrugs off a couple of challenges before confidently splitting the posts to bring Louth level once again.

The Wee County almost follow it up immediately.

Dan McDonnell claims the resulting kick-out and Sam Mulroy finds space outside the arc, but his effort drifts wide of the target.

Monaghan respond immediately.

Micheál Bannigan makes no mistake this time, calmly splitting the posts from the free kick to restore the Farney men's lead with 14 minutes played.

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Louth have hit back in style.

After Micheál Bannigan's goal effort fails to trouble the Louth defence, Dara McDonnell steps up at the other end and drills over a superb two-point score from distance to bring the sides level.

The Wee County almost edge in front moments later, but 19-year-old Monaghan goalkeeper Jamie Mooney produces a brilliant save to deny Craig Lennon from close range.

James Maguire bursts into space and, rather than taking on the goal himself, keeps his composure to split the posts for the Wee County's opening score after eight minutes.

Moments later, captain Sam Mulroy opens his account with a straightforward point to leave just two between the sides.

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