Tasmania became the first team to qualify for the JLT One-Day Cup final after knocking off Queensland by six wickets at Drummoyne Oval on Saturday.
Having bowled the Bulls out for 177 inside 45 overs, the Tigers' pursuit was in trouble at 4-52 inside an hour, but an unbroken fifth-wicket stand of 128 between skipper George Bailey (70no) and Simon Milenko (57no) steered Tasmania to safety and sealed the win with 78 balls to spare.
View the full scorecard here
However, there was a touch of controversy at 4-129 in the run chase when the Bulls were convinced Bailey gloved a leg-side catch to wicketkeeper-captain Jimmy Peirson, but umpire Simon Fry disagreed much to the frustration of bowler Mark Steketee and his Queensland teammates.
Tasmania will face the winner of Sunday's second semi-final between undefeated Western Australia and Victoria at Junction Oval, the venue of Wednesday's decider.
The Tigers entered the clash having progressed straight to the semi-finals after finishing second on the points table after the group stage, while the Bulls – who finished last – beat South Australia in the qualifying final and kept their aim of becoming the first team to win the wooden spoon and premiership in the same tournament alive.
But after they were sent in to bat by Bailey, Queensland's hopes of posting a competitive score were dashed when Tigers debutant Gabe Bell removed hard-hitting opener Max Bryant with his 10th ball.
Bell had his second when Sam Heazlett was caught behind but the big wicket was Chris Lynn, the competition's leading run-scorer and one of the most destructive batters on the planet.
His dismissal for 15 – caught behind by gloveman Matthew Wade from the bowling of seamer Jackson Bird – sucked the wind out of the Bulls innings and from there the Tigers suffocated their opponents.
All five of Tasmania's specialist bowlers collected two wickets, with Gurinder Sandhu's 2-14 from nine overs the pick of the bunch.
"We spoke as a bowling unit about bowling really, really straight," player of the match Sandhu said after the game.
"It's actually a thing we've been trying to do all tournament, just bowl really straight. Most batters hurt you when you give them a bit of width.
"Today it just came out really nicely and I was pretty straight, we all were and got a couple of bowleds and lbws, so today we actually executed our plan."
A score of 177 appeared sub-par, but on a wicket that was showing inconsistent bounce, the Bulls quicks made it look mountainous early on.
Towering quick Billy Stanlake dismissed Wade for a duck in the opening over of the run chase, and then had Australia T20 call-up Ben McDermott caught behind with a rising brute of a ball for 14.
Recalled fast bowler Luke Feldman dismissed Jordan Silk and Alex Doolan to reduce Tasmania to 4-52 in the 14th over and it was level pegging.
But with the experienced head of Bailey and talented allrounder Milenko at the crease, the Tigers were in safe hands.
Milenko brought up his half-century in 55 balls and was outscoring his senior partner until Bailey shook off the appeal for a glove behind – which the Fox Cricket commentators believed to be out – and opened his arms, taking on spin twins Mitchell Swepson and Matthew Kuhnemann.
A soaring six from Bailey's blade brought scores level before a lovely cover drive off Swepson propelled the Tigers into the final.
The 2018 JLT One-Day Cup Final will be broadcast live on Fox Sports and on the cricket.com.au website and app from 10:30am on Wednesday 10 October.