A last-minute own goal from Paddy Kavanagh earned St Patrick's Athletic a 2-2 draw with Shamrock Rovers in the FAI Ford Cup semi-final at Tallaght Stadium.
Chris Turner headed Rovers in front from a Billy Dennehy free-kick, but David McAllister got Pat's level with a cool close-range finish.
Gary Twigg nodded in a Stephen Rice cross to put Rovers back in front before Kavanagh headed Brian Cash's corner into his own net.
The sides will meet again on Tuesday at Richmond Park for the right to play Sligo Rovers in the first final at the Aviva Stadium next month.
It was more heartache for Rovers who saw their title dreams all but end when they conceded two late goals against Sporting Fingal last week.
However, St Pats' were full value for the draw and are still in the hunt for their first FAI Cup win since 1961.
Rovers' injury woes meant that Stephen Rice started at the back, as Pat Flynn filled in at centre-back for the absent Craig Sives and Dan Murray.
Gary Rodgers replaced the cup-tied Chris Bennion in goal for St Pat's, with Stuart Byrne being drafted in as Vinny Faherty dropped to the bench.
In a Dublin derby that had plenty of endeavour but little guile, it was Rovers who went in front after 16 minutes.
Dennehy's free-kick floated to the back post where Turner outjumped Dave Mulcahy, but Gary Rodgers was caught out as the ball dipped over his hand into the net.
Rovers lost James Chambers, who had been injured in a tackle by Ian Bermingham, midway through the first half, with Kavanagh taking his place on the right wing.
Neither side showed too much attacking intent in the opening half hour, but St Pat's were back on level terms after 31 minutes.
A slip by Enda Stevens gave Danny North the room to pick out McAllister and he calmly slotted the ball past Alan Mannus from ten yards.
Pat's were the better side after their equaliser and could have gone in ahead at half-time if North had shown more poise in front of goal.
The striker twisted Aidan Price inside and out but fired into the side-netting with Derek Doyle unmarked in the six-yard box.
Minutes later, Mannus pushed away a header from McAllister after Ryan Guy had beaten Flynn on the right.
Rovers too finished the half with a flourish. Derek Pender ended a storming run by Billy Dennehy. From the resulting free-kick, Rodgers palmed away Stephen Bradley's goal-bound effort.
The defences dominated with both teams working hard to deny each other space on an afternoon full of tough tackles.
Twigg had been struggling with illness during the week but he showed no ill-effects when he put Rovers back ahead on 65 minutes.
Rice dispossessed Bermingham on Rovers' right and whipped in a ball that Twigg met with a powerful header that gave Rodgers no chance.
The game became stretched as the Inchicore side chased a second equaliser with Twigg dragging a shot wide when slipped through by substitute Dessie Baker.
At the other end, North latched onto Stuart Byrne's long ball but shot tamely wide.
Mannus produced a top class save to deny McAllister his second of the afternoon. The winger nodded Bermingham's cross towards the far corner, but Mannus flung himself across to tip the ball away.
Sean Stewart replaced defender Noel Haverty for St Pat's as Pete Mahon urged his side forward. Midfielder Robert Bayly replaced Twigg as Rovers sought to counter St Pat's late push.
Rodgers kept his side in the game in the dying minutes when he kept out Dennehy's effort after Baker had created the opportunity.
Rovers paid the price for that miss as St Pat's drew level in the cruellest way, as Kavanagh directed Cash's driven corner into his own goal.
Kavanagh had the chance to redeem himself in the final seconds, but he fired over the bar with the last shot of the game.