OSBORNE produced a sensational second-half to defeat Culcairn by 18 points in the preliminary final at Walbundrie on Saturday.
Trailing by 36 points at half-time, the Tigers kicked 8.10 to 0.4 to record one of their most famous finals victories.
Sam Livingstone was thrown into the midfield and responded with a best on field display.
While Connor Galvin kicked five goals and 16-year-old All Australian Sam Stenning oozed class every time he went near the ball.
Coach Matt Rava put the victory down to guts and determination.
"Culcairn applied incredible pressure in the first-half and were all over us.
"We spoke about breaking the game down and staying in touch and the boys were unbelievable in the second-half.
Culcairn had many outstanding performers in the first half with Dane Hallinan continuing his outstanding finals series.