Catherine Waycott (27) and Brittany Gliddon (19) guided the Bulls to an eight-point win over Aces Sky in Round 20 of the Bunbury Basketball Association's Women's competition.
Playing at the South West Sports Centre on Friday night, both teams drew level (14-14) at the first change.
The Bulls led by four points at the main break, before widening the gap to 10 at three-quarter time.
Sinking another 14 points in the fourth, the side came away with a 62 to 54 result.
Dunsborough secured the minor premiership with a devastating 110 to 35 win over wooden spooners Eaton.
Adele and Dana East (21 and 20 respectively) excelled for the Oilers, while Chloe Scott (11) and Renee Dowling (10) stood out for the Eagles.
Minor premiers Tornadoes Black went up against a spirited Tornadoes Red in Round 21 of the Men's competition.
Trailing by four at the final change, Tornadoes Red dug deep to level the scores at full time.
A blistering display in overtime saw Tornadoes Black clinch a 79 to 74 victory.
Aces White wrapped up its regular season campaign with a resounding 75 to 62 win over sixth-placed Dunsborough.
Cody Bell top-scored for the victors with 23, ahead of teammate Josh Nimmo (19) and Oiler Jack Flynn (also 19).
Aces Sky retained third spot on the ladder with a 133 to 29 thrashing over an undermanned Eaton side.
South West Slammers' stars Mitchell Keller (27) and Anthony Marinovich (22) were in red-hot form throughout the clash.
The BBA's top teams will return for Round One of the 2019/2020 finals series on February 21.