Harps went in after the opening 45 still a goal to the good, but the attendance wondered just how the visitors didn't find the back of James Gallagher's net on at least one occasion.
After going into the advantage, Harps sat back on their lead and, as a result, the Cats were afforded space while going forward and opened up the Harps rearguard umpteen times, but their lack of composure in front of goal is something which they will be ruing as the make the long trek back to the Marble City.
In part two, Harps had chances for number two, the best of which fell to Jonathan Minnock, but he succeeded in somehow driving wide from a great position at the back post.
Kilkenny got the equaliser they deserved with 17minutes remaining when Caelan Fitzsimons looped a header over James Gallagher into the River End net.
With the crowd fearing the worst and sensing that the inconsistency was set to continue, the hosts were reduced to ten men when centre-back Shane Bradley was given his marching orders by referee Conor Fitzgerald.
But, five minutes later Harps popped up with what turned out to be the winning goal with ten minutes left to play.
Jonathan Minnock's teasing cross from the right wasn't properly dealt with by Stephen Cashin. The Kilkenny netminder failed to hold the delivery and young Davitt Walsh pounced to stab home from close range.
Kilkenny's woes were furthered in the closing stages when Sean L'estrange was dismissed for kicking the ball at Michael Funston.
Harps held on to claim a victory deserved with Kilkenny dominating the chances, but the Finn Park faithful won't be complaining as their side is now the form team in the Division.
Next up is a tricky test against Galway United on Friday night next, in a game which will test this young Harps side to the maximum.
Finn Harps: James Gallagher; Sean McGowan, Jonathan Minnock, Eloka Asokhu, Shane Bradley; Chris Malseed, Barry Curran, David Bell, Michael Funston, Matthew Crossan; Davitt Walsh. Subs: Stephen O'Donnell (for Barry Curran); Shane O'Connor (for Crossan); Darren Meenan (for Walsh).
Finn Harps Dot Com Man-of-the-Match: For the second week running, Davitt Walsh picks up our Man-of-the-Match accolade.
While Michael Funston grafted well in the middle of the park and Jonathan Minnock worked well on the left flank, Kerrykeel native, Walsh, picks up the award for a fine display which epitomised his work ethic.
Determination personified, Walsh capped off yet another fine evening at the office by grabbing the all-important second goal ten minutes from the end of the contest.