Shelbourne took the bragging rights and three points in the first Red Dublin Derby of the decade at a packed Tolka Park on Friday night.
Teenager Jaze Kabia scored the only goal midway through the first half on a night when creativity and clear-cut chances were seldom.
It was the Reds' first league win over their southside rivals since September 2006 – a time when both sides’ managers, Stephen O'Donnell and Ian Morris, were just embarking on their own playing careers.
Both teams were without key players on the night. The Saints matchday squad was absent of marquee signing Robbie Benson while Shels were missing regulars Luke Byrne and Ciaran Kilduff.
O'Donnell’s men arrived with an evident plan of getting the ball wide to Billy King.
The Scottish winger impressed in the Saints’ opening two fixtures and Chris Forrester found him straight from kick-off in the first of a number of link-ups.
It was a tactic employed repeatedly but when King and Forrester found Ronan Hale up front, the striker struggled to find the ball from under his own feet.
A mishit backheel on the halfway line midway through the first period summed up the striker’s difficult night.
Shels had less possession early on but threatened through Karl Sheppard’s delivery from corners. Oscar Brennan nearly opened the scoring when he met his teammate’s delivery, but his low drive was deflected clear from the back of the box.
Shels finally opened the scoring from a corner on 22 minutes when Kabia found himself unmarked to head home another inviting Sheppard cross.
Shelbourne had the lead but only began playing their way into the game during the second half. Sheppard and Farrell had mazy runs from midfield but Luke McNally and Rory Feely diverted the danger for the Saints.
The match slipped out of St Pat’s grasp on 70 minutes when Feely received his marching orders for a second yellow card.
The young centre-back was always playing on the edge after a yellow card in the 11th minute and picked up a second halting Aaron Dobbs’ efforts to collect the ball.
Sheppard was again crucial as Shelbourne flirted with scoring another. The former Cork City man whipped a perfect cross onto the head of Dobbs whose effort hit the bar before bouncing over.
The second half was much the Sheppard and Dobbs show throughout as Kabia was stretchered off with a serious injury.
Sheppard, ever the antagonist, was back on corners in the second half, but his valuable contribution this time was time-wasting.
Yet again, it was Shels who looked most likely to score in the game’s dying embers. Dobbs was nearly through on goal again only beaten by the outrushing Brendan Clarke.
Pat’s looked far from the nabbing the equaliser their fans so sought. Their most ferocious showing at the end of a dark Dublin night was their manager's protestations to the referee after the final whistle.
Shelbourne: Jack Brady; Aidan Friel, Oscar Brennan, Daniel O’Reilly, Alex O’Hanlon; Jaze Kabia (Dayle Rooney 81), Gary Deegan, Ryan Brennan, Karl Sheppard; Shane Farrell (Georgie Poynton 51), Aaron Dobbs.
St Patrick’s Athletic: Brendan Clarke; Dean Clarke, Rory Feely, Luke McNally, Ian Bermingham (Jake Walker 81); Lee Desmond; Darragh Markey, Chris Forrester; Jason McClelland (James Doona 62), Billy King; Ronan Hale (Martin Rennie 62).
Referee: Sean Grant.