Railway Union and YMCA will contest the League Cup final next week after they recorded semi-final wins against Pembroke and Phoenix respectively.
Railway have been the surprise package of the competition and they continued in that vein with another giant-killing against Irish Cup holders Pembroke.
The Park Avenue side were dealt an early blow with the loss of Kevin O'Brien, but another 2007 World Cup veteran stepped forward.
Kenny Carroll and Coach Glenn Querl both scored half centuries as they posted 137 for 8 - always a competitive total with their attack in home conditions.
(Kenny Carroll batting: stock)
'Squacko' top scored with 58 from 54 balls (3 fours, 2 sixes), but it was the late blitz by former Zimbawean U19 international Querl that was to prove decisive as his 54 from 39 deliveries included three maximums, two in the final over.
Ryan Hopkins (3-28) and skipper Fiachra Tucker (2-14) were the most successful with the ball.
Hopkins (2) fell to Oli Perry early in the reply, and although Gavin Hoey (30) and Theo Lawson (44) made steady progress, the home side kept a tight grip on the game.
Prabanshu Kamal bowled his four overs spell for just 12 runs as the required rate grew, and with scoreboard pressure telling, wickets began to tumble as the chase became ever more desperate.
Digamber Mishra picked up three wickets and Hashir Sultan two as Pembroke fell 19 runs adrift.
The final will be an all Sandymount affair as kings of the chase YMCA ousted Phoenix in a low scoring affair.
Batting first, Phoenix lost Ben White early - one of four scalps for Tom Anders, and for the first half of their innings, Jeremy Lawlor and Jamie Grassi got bogged down against the YM attack.
The pair just couldn't get any momentum and ate up too many deliveries as the halfway point loomed. They then both perished in the space of three balls - trapped lbw by Simi Singh and at 42 for 3 after ten overs, it would have taken something special to set a competitive total.
Anders (4-18) ripped out the middle order, and with Harry Tector and Mikey O'Reilly each getting two wickets the innings was in disarray.
Phoenix did get just past the hundred mark thanks to lusty blows from Aaron Cawley and Stephen Black who each made 14, but a total of 102 was below par.
Jack Tector overcame the loss of opening partner Simi Singh to hit four boundaries in a breezy 24 from 18 balls before stepping on his wicket facing Ben White.
When he fell, his in-form younger brother Harry ensured YM were always in control as he cleared the ropes twice in a top score of 32.
(Boundary for Tector)
He and Bobby Gamble fell just short of the target to give the scoreline a closer look than the game was in truth - the margin four wickets.
There will be an extra incentive for the finalists next week, with the winners going on to represent the region in the All-Ireland T20 competition, taking on Cork County at Sydney Parade next Sunday.
The winners of that clash will face either holders CIYMS or Donemana in the decider at Belmont on Saturday 19th.