Shelbourne became the latest side to enjoy an away day victory - but they had to do it the hard way with ten men after Karl Sheppard saw red early on.
Ryan Brennan bagged the only goal of the game at a damp Finn Park in the 30th minute, and the visitors deserved their interval lead.
Battling Harps threw everything at Shels in an absorbing second half, but just could not unlock the stubborn reds defence.
This result lifts the Dublin side to joint fourth in the table while Harps remain third from bottom, a point ahead of Sligo Rovers and Cork City, The opening spell saw both sides settling and adjusting to the very wet, slippery underfoot conditions.
Shels then found themselves down to ten men with just over 11 minutes on the clock as Sheppard was shown a straight red card for a stern challenge near the touch-line on Kosovar Sadiki.
Shels grabbed the lead on the half hour when Alex O’Hanlon sent in a decent cross and Ryan Brennan - who had found space of social distancing proportions - headed past a despairing McGinley.
Indeed, as so often happens, the numerical disadvantaged team seemed to find a pep in their step and Shels could well have doubled their tally in the 38th minute as Aaron Dobbs cut through the home defence from the right and unleashed a cracking shot that wasn’t far off the target.
Harps supremo Ollie Horgan shuffled the pack for the second half and in their best move to date on 57 minutes Shane McEleney found Mark Russell who whipped in a cross aimed at Karl O’Sullivan but Dan Byrne reacted superbly to intervene just in time.
Shels could have got a second when Deegan released Georgie Poynton down the right flank, but although he got into the box his shot from a narrow angle whizzed across the face of goal.
In stoppage time, Shels had a real let-off when defender Dan OReilly put the ball just over his own crossbar.
McGInley; McEleney , Sadiki, Todd; Donnellan (T. McNamee, 43 mins), Connolly, R. Harkin, Coyle (Browne, 80 mins), Russell (G. Harkin, 60 mins); Kogler (Delap, half-time), O’Sullivan.
McCabe ; Friel, D. Byrne , L. Byrne, O’Hanlon; Sheppard, Brennan (Poynton, 70 mins), Deegan, Quinn; Dobbs (Kilduff, 60 mins), Rooney (O’Reilly, 85 mins).
Referee: D. McGraith (Dublin).