In a tense final, Alan Mannus was the hero as he denied Daniel Cleary in the shootout.
Shamrock Rovers made the best of the early chances with Aaron Greene and Ronan Finn going closest to test Gary Rogers on goal. The latter a clever backheel goalwards following a mistake from Daniel Cleary.
Dundalk’s first chance on goal came from a Dane Massey free-kick that sailed over Mannus goal. This was followed by an excellent header from Brian Gartland that was brilliantly saved by Mannus at the back post. Dundalk continued to press late in the half and Daniel Cleary just headed wide from a Sean Murray free-kick.
At the beginning of the second half, both sides tried to exert some pressure on their opposition defences but to no avail. Graham Burke had the best chance for Shamrock Rovers while Sean Murray’s effort was well saved by Mannus. Jamie McGrath had another great chance but his effort went just wide of the post as Dundalk were boosted by the impetus of Daniel Kelly’s introduction.
Shamrock Rovers had a big chance when Finn picked out Burke in the box. He got away from Cleary's challenge but his effort was tipped over the bar by Rogers. And the Dundalk stopper was once again was on hand to deny Burke after he headed Neil Farrugia’s cross straight into his arms. Michael Duffy flashed a shot just wide.
The late in the game came drama. Shamrock Rovers were awarded a penalty after Gary Rogers adjudged to have taken down Aaron Greene. Aaron McEneff was on hand to dispatch the penalty but the action wasn't over as Dundalk went straight back up the other end and scored an equaliser. Duffy latched onto a long ball to despatch it past Mannus.
In extra time both sides tried to create a winner with Shamrock Rovers going closest with Brandon Kavanagh heading just over from a Jack Byrne corner. Greg Bolger also tried his luck from distance only Rogers was alert to the danger. Georgie Kelly thought he had snatched a late winner when his low effort was well blocked by Mannus and trickled wide.
The game went to penalties with Gary O'Neill firing the winning penalty past Rogers to give Rovers the victory.
Dundalk: Gary Rogers, Sean Gannon, Dane Massey, Brian Gartland, Daniel Cleary, Sean Hoare (Georgie Kelly 90), Robbie Benson (John Mountney 111), Sean Murray (Daniel Kelly 61 mins), Jamie McGrath, Michael Duffy, Patrick Hoban (Jordan Flores 99).
Substitutes not used: Aaron McCarey, Jordan Flores, John Mountney, Georgie Kelly, Dean Jarvis, Andy Boyle.
Shamrock Rovers: Alan Mannus, Roberto Lopes, Lee Grace, Ronan Finn, Aaron McEneff, Sean Kavanagh (Neil Farrugia 67mins), Gary O’Neill, Graham Burke (Greg Bolger 90), Aaron Greene (Daniel Lafferty 111 mins), Joey O’Brien, Jack Byrne.
Substitutes not used: Kian Clarke, Greg Bolger, Dylan Watts, Daniel Lafferty, Daniel Lafferty, Thomas Oluwa, Brandon Kavanagh.
Man of the Match: Roberto Lopes.
Booked: Graham Burke 70 mins, Sean Hoare 72 mins. Patrick Hoban 93, Jack Byrne 103, Joey O'Brien 105, John Mountney 105.
Attendance: 33,111