The Sydney Thunder have staggered to a three-wicket win against the lowly Melbourne Stars, booking their spot in the BBL finals.

Chasing just 120 to win at the MCG, the Thunder slumped to 5-60 and were in danger of blowing a golden opportunity to seal a place in the top-five.

The Thunder were staring down the barrel after being 7-88 but Stars captain Adam Zampa dropped a sitter to give Daniel Sams a life.

Sams smashed an important, quick-fire 28 before Zampa (3-26) bowled him in the next over to keep the Stars in the match.

But the damage from Zampa's dropped catch had been done with captain Chris Green and Nathan McAndrew steering the Thunder home with seven balls remaining, securing fourth spot and a home final.

The win knocked Hobart out of fifth spot after the Hurricanes had earlier on Wednesday beaten Brisbane in a thrilling encounter at Blundstone Arena.

The Thunder will host the Heat at Sydney Showgrounds on Friday night in a knockout final.

"Honestly, the batting we need to rectify it," Green told the Seven Network.

"It wasn't good enough unfortunately.

"I think to creep in and have a crack now at finals is exciting for us.

"We have taken them (Thunder fans) on our rollercoaster journey this season.

"But (the Heat) are a side we beat twice this season already.

"We know they are playing good cricket at the back end and we know we will have to play good cricket to beat them."

During the Stars' innings of 7-119, Pakistan spinner Usman Qadir dominated with figures of 3-24.

Qadir claimed the key scalps of Tom Rogers (35), Australia white-ball player Marcus Stoinis and big-hitting Beau Webster to put the Thunder in a commanding position.

Former Australia player Hilton Cartwright top-scored for the Stars with a patient 36, but fell to Thunder captain Chris Green (2-19).

Veteran bowling all-rounder Nathan Coulter-Nile's miserable form with the bat continued, falling for his fourth duck in a row.

The Stars completed a horror campaign on the bottom of the ladder after winning just three of 14 matches.

Earlier, the Hobart Hurricanes pulled off a remarkable two-run victory over the Brisbane Heat.

The Heat were well on track to run down the Hurricanes' modest total of 9-120 when needing 16 runs from the final three overs in Launceston with five wickets in hand.

But the chase imploded, with top-scorer Jimmy Peirson (39 from 37) falling to Nathan Ellis in an 18th over that went for four runs.

Hurricanes quick Joel Paris then got rid of Michael Neser in the next over and conceded just two.

Brisbane required 10 runs for victory off the final over, bowled by part-timer Tim David, but managed just seven despite a heaving maximum from Tim Bazley off the third-last ball.

Bazley needed a four off the final delivery to win the match but could only squeeze a single, leaving the Heat at 8-118.

"What a game. We obviously took a risk bowling myself and Riley (Meredith) out early. We knew full well that Tim (David) was going to have to bowl the 20th (over)," Ellis, who took 2-26, told Fox Cricket.

"Fortunately it just came off. We got a couple of wickets at the right time. For Tim as a part-time off-spinner to do that. It was unbelievable.

"It was just one of those days where any time we came up with a plan it came off."

The Heat, meanwhile, missed a golden chance to secure third spot and hosting rights for "The Knockout" final on Sunday.

The Heat fell to 4-30 in the sixth over of the chase, before a 73-run partnership between Peirson and Sam Hain (26 from 34) ironed out a big chunk of the total.