Wheatley edged out visitors Chipping Norton 8-7 to reach the Oxfordshire Shield final.
Chippy had beaten Wheatley 70-5 in last season’s competition, but this match was a far closer affair.
Ben Ramsdale’s try put the hosts 5-0 up at the break, but Chippy led 7-5 with 15 minutes to go.
Chippy replied with a converted try after an error from Wheatley’s Duncan Dingle.
Replacement scrum half Gavin Stanton won it with a late penalty.
In the final, Wheatley will play either Gosford All Blacks or Blue Boar, who are due to meet in their semi-final on Sunday, February 23.
Abingdon lost 17-0 at Marlborough in the Southern Counties Junior Vase final.
Gosford All Blacks will host Chesham in the Southern Counties Senior Vase final on Saturday.
Their first attempt was postponed due to waterlogging at Stratfield Brake at the weekend.