A massive opportunity awaits both sides when they come face-to-face this evening with the incentive of a Dublin SFC semi-final berth sure to give an edge to proceedings.
Castleknock will enter the tie as marginal favourites having enjoyed successive wins against Division 1 teams St Oliver Plunkett's/Eoghan Ruadh and St Sylvester's in the opening two rounds of their campaign.
Goalkeeper Morven Connolly proved their hero in that 1-13 to 0-12 win over Sylvester's with two penalty saves from Gary Sweeney while at the opposite end of the pitch, James Sherry has developed a handy knack in finding the net for a Castleknock team that relies heavily on the influence of Shane Boland and Ciarán Kilkenny.
Skerries Harps won't be short of confidence after recently gaining promotion to top flight league football in the capital and they had too much firepower for Whitehall Colmcille in the second round, prevailing by 2-20 to 1-10.
Dublin minor of 2015 Stephen Smith was the key attacker on that occasion, kicking seven points from play as well as two frees, but it is the form of 2011 Dublin captain Bryan Cullen that is hugely encouraging from a Harps perspective with his experience a massive advantage to his side.
The reward for both teams is huge with Castleknock just getting the nod to progress to their first ever senior semi-final, albeit by a the narrowest of margins with Kilkenny to the fore.