Shamrock Rovers progressed to their first FAI Cup final since 2002 thanks to a Chris Turner strike against ten-man St Patrick's Athletic in this semi-final replay at Richmond Park.
However, the night ended with a pitch invasion and supporters from both sides fighting.
Turner smashed a superb shot past Pat's keeper Gary Rogers on 70 minutes to set up a meeting Sligo Rovers at Aviva Stadium on 14 November.
Damian Lynch was sent off in the 53rd minute when he pulled at Gary Twigg but the night was marred after the final whistle when fans invaded the pitch and skirmished.
Several fights broke out as players from both sides raced off to the safety of the dressing rooms.
Bottles were thrown by both sets of fans but order was restored by Gardai, stewards and St Patrick's Athletic officials.
It was three years to the very day that Pat's had beaten Rovers 5-0 in a league game at Richmond Park.
Ryan Guy, the only survivor on either side from that night, played a vital through ball to Derek Doyle in the second minute for the home side's first chance but Doyle's shot from 25-yards sailed over the bar.
Pat's continued the early pressure and a sliced clearance from Rovers' Enda Stevens allowed David McAllister try a shot from the right but Alan Mannus in the Rovers goal made the save.
Rovers grew more confident as the minutes ticked away and Billy Dennehy had a shot on target but Rogers was ready and got down well to save Dennehy's low drive.
Dennehy caused concern for Pat's again when he darted in onto Gary Twigg's ball after excellent play from Thomas Stewart, but he couldn't find the target.
Rovers played with 10 men for just under two minutes after referee Tom Connolly ordered Craig Sives to leave the field to change jerseys after a cut to his hand left blood on his jersey.
Following intense Rovers pressure, Pat's made a break but Guy headed wide from Dave Mulcahy's in-swinging cross.
Rovers had a barnstorming start to the second half with Dennehy and Dessie Baker both being denied by superb Rogers saves.
Pat's task was made much harder after 53 minutes when Lynch was sent off for pulling back Twigg just outside the penalty area.
Man-of-the match Baker crashed the resulting free kick wide.
The breakthrough finally came 20 minutes from time when Turner picked up the ball on the right of the area, composed himself, turned, and unleashed a cracking diagonal drive past Rogers and into the back of the net.