Shelbourne 3 St Patrick's Athletic 1: Shelbourne moved five points clear at the top with this fractious win over their Dublin rivals who finished the match with nine players at Tolka Park.
Goals from Jim Crawford, a terrific strike, Jason Byrne, his 18th of the season, and the third a minute from time from substitute Ger McCarthy put the champions, who have a game in hand over Drogheda, in a commanding position to retain their title.
St Patrick's had Keith Fahey and Des Byrne shown straight red cards for dissent.
With three changes, the suspension of David Crawley the only one enforced, Shelbourne reshaped with Ollie Cahill filling in at left-back for the suspended David Crawley. Alan Cawley and Glen Fitzpatrick also came in.
Crawford soon justified his manager's faith with a brilliant goal on 15 minutes. Wes Hoolahan worked the ball in from the left to Stuart Byrne who laid it back to Crawford. The midfielder teed up his shot and planted it into the top left-hand corner of Chris Adamson's net.
A goal of such quality clearly inspired Shelbourne. Darragh Maguire, the St Patrick's defender, got his body in the way to block another long-range effort by Crawford before a flowing move cut open the visitors defence on 20 minutes.
Cawley's chip in from the right was laid off with his chest by Jason Byrne for Fitzpatrick who took the shot first time, half-volleying the ball into the midriff of Adamson. The St Patrick's goalkeeper was then relieved to see Jason Byrne's lob go wide after he had presented the ball to him from a dreadful clearance.
A hiccup at the other end almost undid all Shelbourne's good work on 27 minutes. A poor clearance from Jamie Harris fell for Aidan O'Keeffe, who got in a strong shot which was deflected out for a St Patrick's corner.
A bizarre decision by referee Declan Hanney, who gave a free out instead of what looked a penalty for a challenge by Stephen Quigley on Fitzpatrick, left Shelbourne livid at the break.
They survived a scare when Maguire scuffed a shot from Keith Fahey's free-kick straight at Steve Williams and had another penalty appeal turned down on 54 minutes when Owen Heary appeared to be tripped by Fahey.
On 65 minutes, Cawley's free-kick was knocked down by Harris for the unmarked Jason Byrne to blast past Adamson.
It got worse for St Patrick's as Fahey was dismissed for dissent before the restart. But they were given a lifeline on 75 minutes when Mark Quinless forced the ball past Williams.
Doyle dipped a shot just over, before a dreadful miss by substitute Ger McCarthy as he somehow blazed over an open goal. But he made amends with their third goal on 89 minutes.
Byrne was then also dismissed by Hanney for dissent.
SHELBOURNE: Williams; Heary, Harris, Rogers, Cahill; Cawley (Ndo, 83 mins), S Byrne, Crawford, Hoolahan; J Byrne, Fitzpatrick (G McCarthy, 83 mins).
ST PATRICK'S ATHLETIC: Adamson; Quigley (Dunne, 88 mins.), Foley, Maguire, Byrne; Fahey, Prenderville, Osam (Markey, h/t), Quinless; Doyle, O'Keeffe.
Referee: D Haney (Dublin).
