Brisbane was also regarded as championship contenders in the pre-season, but now have to rally from back-to-back losses to somehow find their way to the grand final.
But Sydney was just too well drilled and too clinical, securing the win with 6-3 victories in the first and second sets.
The Breakers will take a championship point from the match, though, mastering the wind and rain that buffeted the field in the final set to prevail 4-2.
Sydney sets the pace early
Brisbane applied the defensive blowtorch early and Sydney struggled to put players in space, working hard to put Ash Evans in for the first goal.
Then Sydney turned on the defensive screws themselves, Kya Wiya forcing a turnover that led to a Rosie Dawson goal and a 2-0 lead. Another error opened the door for Sydney and Holly Reeve made it 3-0.
Brisbane needed to find a response and some excellent to-and-fro disc movement between John McNaughton and Brett Matzuka paved the way for Rachel Parsons to cross.
Both sides traded goals until Brisbane managed to find the turnover they were looking for, pushing hard on offence late in the set but unable to find the score that they needed.
Sydney then rubbed salt into the wounds with a last-second Dani Alexander goal blowing the scoreline out to 6-3.
Misfiring Breakers open the door for Sydney
A miscommunication between Matzuka and McNaughton coughed up possession again to allow Sydney to start the second set the way they started the first, Mark Wee opening the scoring for the Suns.
Brisbane responded through Lyra Meehan, but Wee provided a leap for the highlight reel to latch onto a long pass and take the lead once more.
The Breakers found another gear and were rewarded with turnovers – and goals to Parsons and Matzuka that gave them their first lead of the set and the match.
From there, it was one-way traffic as Sydney raced in four unanswered goals to seal the match.
Brisbane fight their way back
As the wind picked up at the start of the final set, conditions became trickier to handle the disc.
Freezing Melbourne rain didn’t help and the final set was going to come down to who best handled the conditions.
It took 16 minutes for Sydney to find their way onto the scoresheet, but when they did they scored two rapid-fire goals to set up a nervous finish.
But the Brisbane defence held and Ava Mueller sealed the final set with a time cap goal.