Lee Hughes scored his first goals for Oldham as his side triumphed to condemn Bournemouth to their seventh home defeat of the season.
Hughes struck when he curled the ball home left-footed from 25 yards.
The striker turned provider when he crossed for midfielder Chris Taylor to nod in from five yards.
Hughes grabbed a second with a late penalty after Cherries defender Alex Pearce brought down Taylor before the home side were booed off at the end.
Bournemouth: Stewart, Telfer, Gowling, Alex Pearce, Golbourne (Jason Pearce 89), Henry, Karacan, Cooper, Gradel, Vokes (Kuffour 19), Bradbury (Pitman 58).
Subs Not Used: Pryce, Bartley.
Booked: Henry, Alex Pearce.
Oldham: Crossley, Eardley, Trotman, Stam, Bertrand, Smalley (Hazell 78), McDonald (Allott 54), Kilkenny, Taylor, Hughes (Wolfenden 89), Davies.
Subs Not Used: Bell, Kalala.
Booked: Davies, Trotman.
Goals: Hughes 56, Taylor 70, Hughes 87 pen.
Ref: Graham Horwood (Bedfordshire).