A century from Alyssa Healy and a run-a-ball 96 from Ellyse Perry put Breakers in the box seat.
The unbeaten Breakers were troubled early before a 147-run partnership between Perry and Healy helped them to 6-302.
Healy was rarely troubled as she struck 18 boundaries in her knock of 122 off 109 balls.
The wicketkeeper-batter was dropped on 18 by a diving Heather Graham at gully but offered few other opportunities for her opponents until caught at deep midwicket in the 38th over.
Perry continued the carnage into the final 10 overs but came unstuck by a lunging Emma King at gully just as the NSW No.4 looked certain to reach triple figures.
Sixers English import Amy Jones played a key role in the Fury's run-chase, notching 59 off 64 balls before she was caught by Sixers teammate Sarah Aley off the bowling of Perry.
Perry finished with figures of 2/38 off 8 overs, while Aley also played a key role in bowling WA out for 251, picking up 3/37 off 7.2 overs.
Sixers spinner Lauren Smith also featured for the Breakers, getting through 3 overs in the 51-run victory.