Jamie McGrath scored a stunning goal before providing a sublime assist as holders St Patrick's Athletic came from behind at Tallaght Stadium to book their place in the final of the EA Sports Cup.
Liam Buckley's Inchicore side now meet Limerick in the decider on 17 September at a venue to be decided.
Both sides rang the changes from Friday night's league games. While Rovers made six switches to their starting line-up, St Patrick's started seven players who didn't begin their draw in Derry with midfielder Stephen Kinsella coming in for his full debut.
St Patrick's early game plan was disrupted, though, when Sam Verdon had to be taken off on a stretch with an apparent head injury following a collision with Hoops' striker Sean Boyd.
Rovers had earlier registered the first effort on target when Brandon Miele's free-kick scarcely troubled Conor O'Malley in the St Pat's goal.
Substitute Graham Kelly's mistake then had St Pat's in trouble on 18 minutes. The midfielder's stray pass went straight to Miele who put Dean Clarke in behind down the inside left channel to shoot agonisingly wide
across the face of the visitors' goal as Boyd just failed to connect.
Minutes later O'Malley comfortably dealt with a dipping volley from Boyd as Rovers remained in command.
And the home side's reward duly arrived with the lead goal on 34 minutes.
Boyd's industry saw him win possession from a block tackle with Rory Feely near halfway to put Dean Clarke in the clear. The striker ran on to turn Darren Dennehy before drilling a low shot through the hands of O'Malley, with the ball trickling over the line to the net for no more than Rovers deserved.
Scarcely in the game, St Pat's finally threatened for the first time on 43 minutes when Christy Fagan's header was deflected for a corner after good interplay on the left from McGrath and Mark Timlin.
Rovers were then left kicking themselves as a third successive corner resulted in St Pat's levelling two minutes into added time at the end of the half.
The marking was negligent as Darren Dennehy used his physique to meet Timlin's delivery to head home off the back post.
Despite again enjoying much of the play from the resumption, poor defending cost Rovers a second goal on 57 minutes in the first key note of the second half.
Lee Desmond surged all too easily past Gary McCabe from midfield before deftly slipping the ball to McGrath to score with a delightful first-time rising shot to the top corner past Barry Murphy.
It should have been 3-1 six minutes later. Again the defending was questionable as Fagan got to the near post to meet Timlin's cross only to power his header over the top.
Chasing the game, Rovers' McCabe flashed an angled shot across goal before Boyd was off target with a header from a corner.
But some further McGrath magic sealed St Pat's win on 79 minutes.
The 19-year-old threaded a superb pass through for the run of Fagan who rounded Murphy before rolling the ball to the net.