Shelbourne withstood a late barrage of Bohemians pressure to book their place in a second successive EVOKE.ie FAI Cup final in November.
Noelle Murray's first-half penalty proved the difference in a closely-fought contest in front of a club-record 796 attendance at Tolka Park.
The striker hit the bottom corner from 12 yards after Niamh Prior had clipped Abbie Larkin in the box just before the half-hour.
It was the spark the game needed as there had been little goalmouth action early on as the two teams cancelled one another out.
Abbie Brophy called Shels’ ’keeper Amanda Budden into action with a speculative effort inside the first minute, while Bohs’ stopper Rachael Kelly denied Murray from close range.
There was nothing the former Reds 'keeper could do about Murray’s penalty, however, planted firmly in the corner after Prior inadvertently trod on Larkin’s foot.
Shels' captain Pearl Slattery - who became the second Reds player to reach 150 appearances for the club - headed over from a Murray corner nine minutes from the break.
And Emma Starr went close with a shot from range in injury time following neat touches from Murray and Leah Doyle.
Shels - while far from their slick-passing best - continued to create the clearer chances in the second half.
16-year-old Lia O’Leary burst through on the left from Starr’s pass and looked to pull back for Murray, only for Katie Lovely to make a vital interception.
Bohs began to bear their teeth in the final quarter and sounded a warning when Lisa Murphy drove a 30-yard free kick inches past the post.
Ann-Marie Byrne, who replaced Prior on the left wing at half time, showed neat footwork to dance between two tackles before flashing a shot over.
And another sub, Aoife Robinson, couldn’t keep her volley down after Byrne’s cross had just evaded Kira Bates-Crosbie in the box.
But the best chance arrived two minutes from time as Robinson peeled away from a corner and headed goalwards.
The Shels defence had switched off but Keeva Keenan was, to their relief, alert to clear off the line and ensure the Reds will once again contest the final at Tallaght Stadium.
Shelbourne: Amanda Budden; Keeva Keenan, Pearl Slattery, Shauna Fox, Leah Doyle; Alex Kavanagh, Jessie Stapleton, Emma Starr (Aoife Kelly 90+2); Abbie Larkin, Lia O’Leary (Megan Smyth-Lynch 87), Noelle Murray.
Bohemians: Rachael Kelly; Isobel Finnegan, Lisa Murphy, Katie Lovely, Katie Burdis (Aoife Robinson 75); Chloe Darby, Erin Phelan (Sinéad Taylor 71), Kira Bates-Crosbie; Abbie Brophy, Niamh Prior (Ann-Marie Byrne 46), Erica Burke.
Referee: Neil Doyle (Dublin).
