Debutants Anthony Flood and Gary McCabe gave Bray Wanderers an opening-night win as St Pat's finished with nine men at Inchicore.
Flood - who helped the Saints win the 2013 title - marked his Bray bow with a 22nd-minute opener before McCabe underlined their dominance with a second on 65 minutes.
Substitute Graham Kelly reduced the arrears five minutes from the end but Pat's comeback hopes were dashed by dismissals in the final minute for Aidan Keena and Darren Dennehy.
Pacey winger Dylan Connolly sprung the home side's fragile offside trap and squared the ball for the unmarked Flood to apply a first-time finish. Then McCabe struck a sweet second from just inside the box.
Tim Clancy's failure to clear the ball allowed Kelly to slip in and give Saints a lifeline. But it all went sour for the home team as Keena was sent off for a lunge on Connolly and Dennehy followed him following the resulting melee.
ST PAT'S - B Murphy; Barker, D Dennehy, Peers, Bermingham; Cregg, O'Hanlon (B Dennehy 54); C Byrne, Lunney (Keena 70), K Byrne (Kelly 54); Fagan.
BRAY WANDERERS - Cherrie; Douglas, Kenna, Clancy, Lynch; Sullivan, Buckley; Greene, McCabe (Brennan 83), Connolly (Moore 90+2); Flood (Pender 72).
Ref - D Tomney (Dublin)