Donnybrook remains in fifth spot on the South West Football League ladder after claiming three wins from six games.
Round Three saw Bunbury kick three unanswered goals against the Dons in the second quarter.
Donnybrook improved in the second half, while the Bulldogs continued their momentum up until the final siren.
Bunbury went on to secure a 10.9 (69) to 8.18 (66) victory, in front of fans at PC Payne Park.
Tyler Patterson (three goals) and Thomas Omodei (two) starred for the visitors.
Bouncing back from the loss to Bunbury, Donnybrook earned its second win of the season in Round Four.
Battling Augusta-Margaret River and overcast conditions at VC Mitchell Park, the Dons trailed by four points at quarter time.
Behind by six at the main break, Donnybrook returned to the field and picked up steam in the second half.
Goals to Sean Lynch, Brett Robinson, Chris Atthowe, and Jace Cormack put the home side in front by 21 at three-quarter time.
Donnybook stormed home to claim an impressive 11.11 (77) to 7.12 (54) win.
The side then obliterated seventh-placed South Bunbury at Hands Oval.
Donnybrook booted four goals in the opening term, before kicking another three in the second.
Following a scrappy, low-scoring third term, Donnybrook returned to form in the fourth.
Losing 0.0 (5) to 11.11 (77) in Round Five, South Bunbury posted the lowest score in South West Football League history.
The Dons put up a brave fight against league leaders Harvey-Brunswick-Leschenault, at VC Mitchell Park, in Round Six.
HBL led by 21 at quarter time after racking up six goals to two in the first term.
Trailing 8.3 (51) to 3.5 (23) at the main break, the Dons came back to kick three unanswered goals in the third quarter.
But the Lions continued their unbeaten run with a 9.8 (62) to 7.13 (55) victory.
Donnybrook star Brett Robinson slotted three goals in Sunday's game.
Travelling to Glen Huon Reserve, the Dons will face off against the Eaton Boomers in Round Seven.
