Bunbury suffered a shock loss at the hands of Augusta-Margaret River on Sunday afternoon.
Coming together at Payne Park, the crowd had anticipated a tight clash between two exciting teams.
The Bulldogs took control before booting four goals to two in the opening term.
Trailing by 11 points at quarter time, Augusta-Margaret River came back to kick six goals to one in the second.
The Hawks posted another four goals to one in the third, before notching up a 17.8 (110) to 7.8 (50) win.
Harry Taylor (four), Matt Jukes (three) and Braden Smith (three) enjoyed a day of accurate kicking while Jonathon Coghlan (one), Beau Morgan, Lincoln Adams, Banjo Watkins (two), Mitch Payne (two) and Tom McDonald (two) were all impressive on ground for the Hawks.
Bunbury faces an uphill battle against the Eaton Boomers, this Sunday.
The Eagles capped off their season with a commanding victory over Donnybrook, at the Collie Recreation Ground.
Following a tight first quarter, goals to Hayden Yarran (three goals) and Jeffrey Smith (one) put the Eagles in front by six at the main break.
Setting up plenty of chances, Collie extended its lead to 21 before three quarter time. Playing well around the ground, the home side collected a 11.7 (73) to 7.5 (47) win.
South Bunbury was handed a crushing 103-point defeat to the Boomers, at Glen Huon Reserve.
After an exciting opening term, Eaton scored five goals to two in the second quarter.
Leading by 27 midway through the clash, the Boomers posted a whopping 14 goals to two in the second half.
Jarrod Humphries (12) led Eaton to a 22.13 (145) to 6.6 (42) result.
Busselton secured its sixth win of the season with a 94-point thrashing over wooden spooners Harvey, in Round 18.
Reegan Mrsich (eight), Bailey Sanford (three), and Mitchell Tenardi (two) put the Magpies ahead by 20 at quarter time.
With the Bulls' chances fading rapidly, Busselton slotted eight goals to one in the second term.
Following a nine-goal haul in the second half, the Magpies celebrated a 22.12 (144) to 7.8 (50) victory.
Harvey-Brunswick-Leschenault secured the minor premiership with a 17.12 (114) to 5.4 (34) win over Carey Park.
The Lions kicked a resounding seven goals to one in the first half, before claiming ten majors to four in the second. Taine Williams (four) was one of HBL's ten goal-scorers on the day.
The South West Football League finals series kicks off this weekend, with games at Gloucester Park and Glen Huon Reserve.