Derry City and Shelbourne will have to do it all again on Wednesday night, following a hard-fought FAI Ford Cup 1-1 draw at sun-soaked Brandywell.
The visitors took a half-time lead thanks to David Cassidy's fifth-minute strike.
But Derry dominated the second half of the cup semi-final encounter and deservedly drew level thanks to David McDaid's 16th goal of the season.
The Brandywell men had two changes to their side which defeated Dundalk, with manager Declan Devine making a major call by starting duo Stephen McLaughlin and Rory Patterson.
Patterson, who was making his first start in over a few months, came in for Ruaidhri Higgins, while McLaughlin, who was also returning from a number of weeks out, replaced youngster Barry McNamee.
Shels took the lead on five minutes when a lucky bounce of the ball fell perfectly into David Cassidy's path and the skipper coolly made no mistake side footing home from the left hand side of the box.
Soon after the home side went close to levelling things but Patrick McEleney's tremendous 25-yard drive was superbly tipped over by a full-stretched Chris Bennion.
Just after the half-hour mark the Dubliners had a super chance when Glen Cronin found himself totally unmarked in a packed City penalty box, but the midfielder's header, from Paddy Kavanagh's corner, was straight at Doherty.
Early in the second half Declan Devine's side thought they had equalised but Stewart Greacen's celebrations was cut short by referee Damien Hancock, who correctly disallowed the goal, after the big centre-back had fouled Shels ‘keeper Bennion in his attempts to put the ball into the net.
The Candystripes, who started the second half on the front foot, deservedly equalised thanks to that man McDaid.
A fantastic Dermot McCaffrey cross from the left found McDaid, who ghosted in at the back post to head home despite Bennion's best attempts to keep the effort out.
The home side continued to pile forward for the all important second goal but on 78 minutes Simon Madden's super volley from 20 yards, took a horrible bounce just in front of Bennion, who did well to push the ball over.
Derry City: Doherty, Madden, S McEleney, Greacen, McCaffrey; P McEleney, Molloy, Deery, McLaughlin; Patterson, McDaid. Subs: McNamee for Patterson (70); Farren for McLaughlin (84); Brolly for McDaid (90).
Shelbourne: Bennion, Boyle, Paisley, Cronin, Cassidy, Hughes, Dawson, Kavanagh, S Byrne, P Byrne, Ryan. Subs: Gorman for Hughes (62); C Byrne for Cassidy (77); Shortall for Ryan (90).
Referee: Mr Damien Hancock (Dublin).