Josh Brown's record-breaking century has powered Brisbane Heat to a 54-run defeat of Adelaide Strikers and into the Big Bash League decider.

The Heat opener pulverised a tournament-record 12 sixes to go with 10 fours in his 57-ball 140, the innings blazing Brisbane's trail to Wednesday's SCG final against the Sydney Sixers.

Chasing 215 to win, the Strikers were bowled out for 160, with Nathan McSweeney taking 3-3 in the final over to seal a 54-run victory.

Brown's was the highest score in a BBL finals game and the equal second-fastest hundred in tournament history, hitting Cameron Boyce for six over mid-on to bring up the milestone off 41 balls.

After Brown was finally dismissed in the 17th over with the score at 192, the Heat lost 4-5 and scored just 14 from the final three overs to bring the visitors back into the contest.

But a two-wicket over from strike weapon Spencer Johnson (3-20 off four overs), picking up key pair Matt Short (19 off nine balls) and D'Arcy Short (seven off 13), helped put the Strikers back in their box.

Brown, a 30-year-old bat-maker who forced his way into a BBL contract last season through sheer weight of club cricket runs, was on pace to beat Perth blaster Craig Simmons' 39-ball mark.

He had to settle for a share with Glenn Maxwell for second, in the process easily eclipsing Chris Lynn's 49-ball century that was the previous fastest ton for the Heat.

It was also the third-highest BBL score behind Maxwell (154 not out) and Marcus Stoinis (147 not out).

Brown reached 50 in 22 balls, the same amount he faced on Friday when he made a sluggish 15 that featured countless air swings in a loss to the Sixers.

The Carrara Stadium wicket had firmed since then, with Brown immediately into rhythm as he targeted midwicket when bowlers dropped short and cover if they over-pitched.

A rare slice of luck came as he entered the 90s with a skied pull shot that fell between four fielders, Brown otherwise picking his spots with brutal precision.

Boyce (2-50) and Lloyd Pope (2-39) bounced back from Brown's early assault, while David Payne (2-17 from three overs) was also effective.

Chasing a mammoth score, Brisbane pace bowler Spencer Johnson was breathing fire.

He dismissed Adelaide's openers D'Arcy Short (seven from 13) and Matt Short (19 from nine) followed by Jake Weatherald, who was the architect in the Strikers' upset of Perth Scorchers three days ago.

The required rate soared past 15 runs an over, but Matt Kelly (41 off 24) was defiant until swatting a Paul Walter delivery straight into Michael Neser's safe hands.

The Heat lost to Perth in last year's decider and will chase their first title since the BBL's second season, while the Sixers can claim a fourth title in their seventh final.

AAP