In a game of very few chances, James English scored the winner in the last three minutes.
It had been a glorious afternoon in Dublin, but Stradbrook is Blackrock's rugby ground, and it meant the pitch had an effect on the game, as the ball tended to bobble rather than role.
This resulted in a first-half that was quite disjointed at times. Mark Hughes's tenth minute volley from the edge of the box was the best of the early exchanges, but his effort didn't dip enough. The next chance fell to the hosts, as Marty Waters tried to chip Delaney from the left edge of the box.
The Shelbourne keeper was rooted to the spot, but the ball went wide to the right. The best half of the chance came Shelbourne's way in the 28th minute. Adam Evans crossed, and the ball eventually sat up for Dale Rooney.
His scissor-kick went to the wrong side of Michael Kelly's goal. There was also an edge to the game, as James O'Brien and Karl Byrne were both booked for either side in that first period. The second forty-five was similarly untidy.
Adam O'Connor did it all himself in the 55th minute, but his shot from the edge of the box was just wide. O'Connor had another effort in the 67th minute, but his strike from the edge of the box was always rising.
But just when it looked like a draw was inevitable, English scored the winner. Substitute Chris Lyons put the ball in the box.
English took a touch, and buried it in the left corner. It's a third win on the bounce for Owen Heary's side, and it moves them up to second in the First Division table.
Report courtesy of sseairtricityleague.ie - with thanks
Cabinteely : Michael Kelly, Karl Byrne (Jason Byrne 85'), Kevin Knight, Conor Keeley, Christian Lotefa, Daire Doyle (Adam Harney 90'), Jack Watson, Anthony Dolan, Joe Doyle, Kieran Waters, Evan Galvin.
Substitutes not used: Jack Menton, Aaron Robinson, Paul Fox, Robert Duggan, Stephen Ball.
Shelbourne : Dean Delany, Adam O'Connor, Reece McEnteer, Derek Prendergast, Alan Byrne, Adam Evans, Mark Hughes, Dale Rooney, James English, James O'Brien, Lorcan Shannon (79').
Substitutes not used : Jamie Quinn, James Brown, Jack Tuite, Dylan Grimes, David O'Leary, Aaron Ashe.