St Patrick's Athletic 2 Shamrock Rovers 0: Shamrock Rovers' apparent inability to defend corners cost them again as goals early in each half from Robbie Doyle and Darragh Maguire saw landlords St Patrick's leapfrog them in the table.
It was a fourth league defeat in succession for a Rovers side - second in the table in May - which now finds itself fourth from bottom.
There were to be no home comforts for tenants Rovers as St Patrick's blitzed them early on to take a fourth-minute lead. Having conceding three goals from corners in their previous two games, lessons clearly hadn't been learned by the Rovers defence which fell behind to yet another one.
A Mark Quinless delivery wasn't dealt with and the ball broke for Robbie Doyle on the edge of the area. His languid volley appeared to deceive Noel Mooney and beat the Rovers' keeper at his left-hand post.
That difficulty in defending from dead-ball situations was all too evident again as St Patrick's might have added a second goal on 14 minutes. The run of defender Maguire wasn't tracked and he met Des Byrne's free-kick at the back post with Mooney having to make a reaction save to palm the ball away.
Rovers found their composure as the half wore on and some good footwork from Trevor Molloy opened up the St Patrick's defence.
Shane Robinson had a shot blocked away by Maguire before St Patrick's captain Colm Foley put his body in the way of Keith O'Halloran's follow-up.
But St Patrick's regained almost total control of the match on the resumption, scoring a second goal on 54 minutes.
Again a corner, this time from Byrne, wasn't defended. Foley's header was cleared off the line by Mark Rutherford but Maguire followed up to blast home the rebound.
St Patrick's Athletic: Adamson; Quigley, Foley, Maguire, Byrne; Quinless, Prenderville, Osam (Casey, 69 mins), O'Keeffe; Doyle (Knight, 79 mins), Markey.
Shamrock Rovers: N Mooney; Robinson, McGuinness, Palmer, Gough; O'Brien, O'Halloran, Caffrey (Cousins, 77 mins), Rutherford; Mooney (Kelly, 65 mins), Molloy.
Referee: Paul McKeon (Dublin)