After dominating the competition all year, the Storm last night advanced to the club's eighth season decider and second in a row.
With Cronk set to retire or move to a Sydney-based club after season 2017, it ensures the Storm will have plenty of motivation as they get set to face the Sydney Roosters or North Queensland on Sunday week at ANZ Stadium.
After being wasteful in the first 40 minutes, the minor premiers went into the breakup 8-0 but turned it on the second stanza, running in three tries including a Billy Slater double.
The Storm, near unbackable title favourites for most of the year, dropped just four games all season and racked up their ninth win in a row against the Broncos.
In front of a 28,821-strong crowd at AAMI Park - the biggest attendance for a Storm home game - milestones tumbled with Slater moving into second on rugby league's try-scoring list when he crossed for his 181st career four-pointer in the second half.
And when Nelson Asofa-Solomona barged over the top of three defenders to make it 18-0 in the 66th minute, skipper Cameron Smith became the first player to bring up 1000 goals with the resulting conversion.
The Storm had a host of missed opportunities in the first half with Suliasi Vunivali dropping it with the line begging, while Felise Kaufusi was only prevented from scoring by an Anthony Milford ankle tap.
However, the Broncos were rarely in the game in the second half, as they lost skipper Darius Boyd to what appeared to be a recurrence of the hamstring injury which kept him out for the previous two weeks.
The Storm went into the sheds up 8-0 after Curtis Scott popped a miracle ball for a flying Josh Addo-Carr in the shadows of the break.
From there, it was the Storm show with Slater scoring the first of his double in the 60th minute to kick off an avalanche.
Photo: Photosport Melbourne Storm rugby league player Cooper Cronk.