Clontarf and Terenure College will meet in a repeat of last year's Energia All-Ireland League Division 1A final when this season's title race is decided at the Aviva Stadium on Sunday, 7 May.
The Dublin rivals, the top two finishers in the table, won through to the decider in contrasting style, with reigning champions Clontarf edging out Young Munster 13-12 in a tense tussle at Castle Avenue.
The Lakelands Park faithful roared Terenure on to their second successive final appearance, which was sealed by a 30-12 victory over Cork Constitution.
Caolan Dooley kicked 20 points and Adam La Grue and Jordan Coghlan claimed a try each.
Cork Con gave themselves a mountain to climb when falling 18 points behind in wet conditions.
Two early Dooley penalties gave Terenure the upper hand, the first coming from a scrum penalty on the 10-metre line.
Nure's backs gave a glimpse of their attacking class in the 22nd minute when quick hands releasing full-back La Grue for the left corner.
Number eight Coghlan crossed six minutes later, with Con's defence missing sin-binned centre Niall Kenneally.
Jonny Holland's men were unable to convert some late pressure into points before half-time, but replacement James Murphy barged over in the 49th minute - followed by an Aidan Moynihan conversion - to reduce the arrears to 18-7.
Nure, who are gunning for a League and Cup double, turned to goal-kicking winger Dooley to settle things down again.
His reliable right boot banged over two more penalties to leave 17 points in it with 13 minutes remaining.
Con did rally again with a Cathal O'Flaherty try in the corner, but a late brace of Dooley kicks - the last one from far out - ensured Sean Skehan's side got the job done in clinical fashion.
Meanwhile, fourth-place finishers Young Munster fell agonisingly short of dethroning Clontarf who relied on hooker Dylan Donnellan's 22nd try of the season to reach their third straight league final.
The sides were locked level on six points apiece at the break, as full-back Tadhg Bird and Conor Hayes landed two kicks each.
The slippery ball made for a tight forwards-dominated contest and there was little in it.
A second Bird kick reward the home scrum on the half hour mark, and Munsters did leave points behind them despite levelling.
A costly knock-on robbed them of a try-scoring position, while Hayes had two misses from the kicking tee.
The Cookies led 9-6 entering the final quarter, as Hayes was able to fire over brilliantly from 40 metres out to reward Ronan O'Sullivan's breakdown work.
Both teams had to cope with yellow cards, the hosts losing Steve Crosbie and Munster Academy centre Fionn Gibbons was also binned.
Tarf seemed to react the better, winning a couple of scrum penalties to put themselves back on the front foot.
It was their ball-carrying power that propelled Donnellan over in the 63rd minute, his quick tap and surge to the line continuing his incredible try-scoring run.
The Galway-born front rower, who previously played for Biarritz Olympique and Yorkshire Carnegie, was also Division 1A's top tryscorer last year with 19 tries.
Bird tagged on a crucial conversion, and despite Hayes taking his tally to a dozen points with just over 10 minutes remaining, Munsters ran out of time as Tarf booked a return trip to the Aviva.
Shannon moved within 80 minutes of retaining their top-flight status after beating Old Wesley 24-6 in the promotion/relegation play-off semi-final.
Former captain Chris Banon used an 8-9 scrum move with Miah Cronin to score a decisive 50th-minute try for Highfield, who ended Old Belvedere's hopes by winning 19-17 at Ollie Campbell Park. They will travel to Thomond Park for the final.
Banbridge will be playing Division 2A rugby next season after losing 20-18 to MU Barnhall in their play-off clash, as 15 unanswered first-half points set the tone for the Blue Bulls whose promotion hopes hinge on a 6 May final against Blackrock College at Stradbrook.
A converted try from Peter Quirke, with five minutes remaining, saw Blackrock squeeze past Nenagh Ormond on a 10-8 scoreline.
James Blaney's men are striving for back-to-back promotions after coming up from Division 2B last season via the play-offs.
There were two more closely-fought games in the Division 2A promotion/relegation play-off semi-finals.
Calum Goddard and Kuba Wojtkowicz both crossed for Sligo in response to Ignacio Garcia's early try, but a late penalty from Harry Byrne, who finished with 11 points, saw UL Bohemians prevail 16-14.
Dungannon will be away to UL Bohs in the deciding game, having got the better of Galway Corinthians to take a 16-12 verdict.
Galwegians suffered relegation at the hands of Bruff, who won their Division 2B promotion/relegation play-off semi-final 24-12.
Skerries, the second-place finishers in Division 2C, will have home advantage in the promotion decider.
They advanced to face Bruff after a quartet of penalties from full-back Ronan Mulcahy saw them overcome Tullamore 12-3 at Holmpatrick.
