The returning Jack Byrne and veteran goalkeeper Alan Mannus were the shootout heroes as Shamrock Rovers lifted the President's Cup to get the domestic season under way.
Chief new signing Eoin Doyle announced his return to the League of Ireland in typical fashion with a poacher's goal to put St Patrick's deservedly ahead early in the second half.
But Rovers skipper Ronan Finn punished an unfortunate mistake by Saints' new goalkeeper Joseph Anang to equalise.
With no further scoring in a tight contest, spot-kicks were required at Tallaght Stadium.
Mannus saved skipper Chris Forrester's third St Pat's penalty in the only failure from the spot.
Richie Towell, Graham Burke, Sean Hoare and Gary O'Neill all scored for Rovers before Byrne sent Anang the wrong way with the crucial fifth.
Either side of Forrester's miss, Eoin and Mark Doyle, Tunde Owoloabi and Adam O'Reilly were successful from 12 yards for St Pat's.
Rovers initially enjoyed a little more of the ball on a chilly, windy night in front of UachtarÃ¡n na hÃ‰ireann among the crowd of 5,426. But it was St Pat's who had the first shot in anger on 11 minutes, if Mark Doyle's effort lacked conviction allowing Mannus to comfortably save.
The 23-year-old Doyle's composure then badly let him down five minutes later as he miskicked dead in front of goal, much to Rovers' defender Sean Hoare's relief after his attempted back pass allowed Eoin Doyle, one of six new signings in the visitors side, to set up the chance.
As Rovers surprisingly struggled to get a foothold in the game, St Pat's remained the better side and they had the home defence at sixes-and-sevens just past the half hour.
First, Forrester's sublime ball sent Eoin Doyle racing through to bring a fine save from Mannus.
Frantic Hoops defending then followed from Darragh Burns' delivery.
Dylan Watts cleared a Jack Scott header off the line before Mannus saved superbly at point-blank range from Mark Doyle's follow up as Rovers somehow survived falling behind.
The somewhat frustrated home faithful had to wait until the 43rd minute to see their side register an effort on target.
Byrne was instrumental with a delightful looped ball down the inside left channel for the run of Danny Mandroiu, whose half-volley was turned round a post by Anang.
And though Rovers looked to have a little more about them on the resumption, St Pat's exposed them on the counterattack to take a deserved lead on 50 minutes.
Mark Doyle turned Sean Gannon one way and then the other to deliver a cross that wasn't cleared.
The ball fell for Jamie Lennon on the edge of the area, whose shot Mannus could only parry, gifting Eoin Doyle a poacher's finish as he rifled to the net from just yards out.
Rovers manager Stephen Bradley injected the quality of Burke, Towell and Rory Gaffney off the bench on 63 minutes.
It immediately gave Rovers an energy they had lacked and they were level four minutes later, if the beneficiaries of a goalkeeping howler.
Burke put Neil Farrugia away on the left. Anang spilled the cross at his near post, with the ever-alert Finn scooping the rebound into the net.