Lacken came up with the second-half goods to see off Cuchulainns in this evening's senior championship play-off at St Matthew's Park in Crosskeys.
In what was a second meeting in seven days between these two teams, with Lacken having nabbed a late draw the last day, Stephen Brady's 25th minute goal propelled Finbar O'Reilly's men towards the half-time lead and in the second-half inside men Conor Finnegan (0-3) and Raymond Galligan (0-3) did more irreversible damage.
Cuchulainns were made to rue two goal chances that came back off the post at the end of each half, as they ended up chasing the game in the latter stages which suited Lacken to see out the win and advance to a quarter-final date with last year's beaten finalists Castlerahan.
Niall Lynch's fired-up side couldn't really have asked for a better start to this contest, sending over the first three scores from marksmen Evan Doughty (2 frees) and Bryan Magee, but an early black card for Seamus Clarke certainly did not help their cause.
The loss of Clarke, who had been involved in so much of the Mullagh men's good play last time out, saw an early introduction for David Carolan to proceedings as his side looked to continue their early flow.
It was around the seven minute mark that their opponents got up and running thanks to a trademark left-footed effort from Niall McKiernan which went over with the help of the crossbar.
Magee's second from play cancelled out Brady, scorer of 1-2 over the hour, and Cuchulainns' number 10 would make no mistake from 35 metres to restore his side's three-point advantage with 17 minutes having passed.
Some superb forward play from McKiernan and Finnegan released Craig Lanauze for Lacken's third point, prior to McKiernan and Doughty cancelling each other out with frees, and by that stage the would-be winners had gained their foothold around the centre.
A slick move down the left flank saw Finnegan and Thomas Galligan combine and put Brady through and the corner-forward supplied the neat finish beyond Christopher Magee which had the umpire going for the green flag.
Brady's strike put Lacken into their first lead, which they lost to Doughty's fourth free before regaining it again on the interval's eve thanks to Thomas Galligan feeding Brady through in space.
The Sky Blues could well have lost it again on the stroke of half-time had Carolan's rasping shot hit their net rather than smack off the post, but they averted the danger and went in at the break with a slender 1-5 to 0-7 lead to work with for the second-half.
James Moynagh set-up Raymond Galligan to double that lead early in the restart and although Adam O'Reilly erased it at the other end, Lacken were really starting to up their conversion rate with that man Galligan landing an absolute gem from the right corner and Finnegan backing it up with one of his own soon afterwards.
Magee and McKiernan (frees) made sure it was still a three-point game going into the final quarter and it would be the margin for the last 10 as well, after Declan Brady's point was responded to by Adrian Taite bursting forward from centre-field and crashing the ball over Colin Comerford's bar.
Lacken hit the next three scores for the close out however, with Raymond Galligan and Finnegan (2) coming up trumps when it mattered most, which left Lynch's men chasing goals in injury-time.
Gary Daly had a chance flash wide prior to Christopher Tully hitting the butt of the post on the hour mark, which meant the Cuckoos would have to settle for two Magee frees instead as John Flanagan's red card prior to the final whistle capsulated the frustration of this defeat for them after having had their opponents on the ropes seven days previous.
Lacken: Colin Comerford; Kevin Shanaghy, Daithi Wilson, Declan Brady (0-1); Craig Lanauze (0-1), James Galligan, Shane O'Reilly; Thomas Galligan, Niall McKiernan (0-3, 2f); Shane Finnegan, Conor Finnegan (0-3), Damien McKiernan; Stephen Brady (1-2), Raymond Galligan (0-3), James Moynagh. Subs: Paul Leddy for S Brady (47mins), Killian Galligan for R Galligan (55), Martin Brady for D Brady (58).
Cuchulainns: Christopher Magee; John Flanagan, Aoghan Daly, Christopher Tully; Killian Lynch, Donnacha Dunne, Gavin Daly; Adrian Taite (0-1), Seamus Clarke; Bryan Magee (0-5, 3f), Gary Daly, Conor Finnegan; Evan Doughty (0-5, 5f), Conor Smith, Adam O'Reilly (0-1). Subs: David Carolan for S Clarke (4mins, b/c), Shane Smith for E Doughty (53), Andrew Mooney for Gavin Daly (53).
Ref: Noel Mooney (Cavan Gaels)Tweet