Three goals inside the last 16 minutes saw Drogheda United snatch a 3-1 victory from the jaws of defeat at Tolka Park.
Having trailed 1-0 at the interval, Mick Cooke’s side fought valiantly to get back in the game and drew level in the 74th minute through substitute Declan O’Brien.
O’Brien was on the field only three minutes when he popped up two yards out to head home Ryan Brennan’s cross from the left.
The equaliser changed a game which for a long time seemed destined to go the way of the home side.
Shels were the better side for much of the game and were good value for their one-goal lead at the break.
As the clock ticked into injury-time at the end of the first half, Seán Brennan sent a corner over from the right hand side. It was met by the head of Brian Shortall six yards out and in the centre of the goal and Gabriel Sava had no chance.
Earlier, Dean Kelly hit the side-netting with a well-struck free-kick from just outside the box, and Seán Brennan looked set to score against a Drogheda side containing his two brothers, Ryan and Gavin.
His cracking shot from 30 yards on 27 minutes was matched by Sava’s athleticism between the Drogheda sticks and his overhead attempt after 38 minutes was an audacious effort.
Brennan himself broke down the left before releasing Phil Hughes, whose cross was met by the head of Kelly. He put it back across the face for Brennan to attempt the bicycle kick which went just over.
Before Shels scored, Drogheda might have taken the lead themselves, Brian Gannon was unlucky to see his volley from just inside the box come back off the upright, but it was the home side who went in ahead at the break.
Shels could have doubled their lead a minute into the second half. Good work from Adam Hanlon released Kelly down the right. He found Brennan with his cross but the header was straight at Sava.
It all got a bit scrappy until Drogheda introduced O’Brien, and within three minutes the game was turned on its head with the equaliser.
Five minutes from time Drogheda went ahead through Gary O’Neill. He headed home from close range when David Cassidy sent in a free-kick from wide on the right-hand side deep in Shelbourne territory.
In the last minute, Drogheda’s victory was ensured through an O’Brien penalty. Jack Memery chopped down late sub Michael Daly inside the box and O’Brien stepped up to slot home his fourth penalty of the season, and double his tally for the night.
United climb to 11 points from eight games, while Shels remain firmly mired at the wrong end of the table with just a single point to show from their opening seven games.
Shelbourne: Ger Hanley, Brian Shortall (Mark Leech 88), Jack Memery, Graham Gartland, Seán Brennan (Robert Bayly 88), Paul Crowley, Philip Hughes, Dean Kelly, Pat Flynn, Stephen Hurley, Robert Cornwall (Adam Hanlon 24)
Drogheda United: Gabriel Sava, Derek Prendergast, Paul O’Conor, Ryan Brennan, Gary O’Neill (Michael Daly 89), Gavin Brennan, Shane Grimes, Graham Rusk (Declan O‘Brien 71), David Cassidy, Brian Gannon, Alan Byrne
Referee: R Rogers