St Pat's moved to the top of the Premier Division table thanks to Danny North's penalty against Bray Wanderers at a wet Richmond Park.
The spot-kick came after 56 minutes when referee Neil Doyle sent Adam Mitchell off for a deliberate hand ball. North stepped up and tucked his spot kick past Matt Gregg in the Bray goal.
St Pat's held on despite severe Bray pressure and, coupled with Shamrock Rovers' defeat to Sligo Rovers, moved to the top of the table. The top two meet in Tallaght on Sunday week.
The last time these two sides met in Inchicore in early March, UCD came back from 2-0 down to record a famous and dramatic 3-2 victory.
That was arguably the victory that firmly set the Seasiders on their current run of excellent performances that sees them challenging at the top of the table.
And that fighting Bray spirit was very much in evidence from the beginning of this match, played in miserable, driving rain by the banks of the Camac.
Plenty of early pressure and possession by Bray was followed on 15 minutes by a superb move from the back.
Several men in green and white stripes had vital touches before the ball arrived at the feet of Daire Doyle who played a low ball across the Pat's six-yard box.
John Mulroy was best placed of the inrushing Bray men but Pat's goalkeeper Gary Rogers was first to the ball.
Saints had a slow start with their best chance of the first 45 minutes coming five minutes before the break with a long-range shot from Daryl Kavanagh that was saved by Gregg.
Stephen Bradley then put in a corner two minutes later, which landed perfectly for Derek Doyle but the midfielder missed the opportunity.
Derek Doyle and North had chances for the home side after the restart before they took the lead on 56 minutes.
Referee Doyle flashed a red card at Mitchell for deliberate hand ball and pointed to the penalty spot. North took the spot kick and sent the ball neatly past Gregg into the bottom left corner.
Gregg then came to the rescue for Bray on 69 minutes with a fine save from Evan McMillan's header after a Stephen Bradley corner and again on 80 with a save from sub David McMillan.
Bray boss Pat Devlin made a triple substitution on 84 minutes but it was too little too late and he himself was banished to the stands for dissent as the game entered injury time.