Corby Kingswood Black made a slow start and went behind.
This spurred them on and they equalised through Luke Hayo late in the first half.
Blacks got the winner in the first half of extra-time through Ricky Carr.
They battled right through to the end to go into their first cup final with a fantastic performance from the whole team.
Colts were outstanding despite the defeat and produced a host of chances. They battled for the entire game and were a credit to themselves.
Corby Kingswood Black: Ricky Carr, Samuel Charter, Laine Copeland, Conor Ferguson, Costin Gibson, Luke Hayo, Jack Ilko, John Lloyd, Shane Macbeath, Ben McLean, Martin Louis, Joe O’Donovan, Stefan Sabadi, Anthony Smith, Daniel Smith, Aiden Welsh. Corby Kingswood Black player of the match: Ricky Carr.
Higham Colts: Cameron Arnold, Danny Brayfield, Charlie Brooks, Jack Carroll, Reece Gilbert, Taylor Ormond, Matt Owen, Charlie Rice, Nathan Rosshart, Kian Taylor, Lewis Warner, Ben Welsh. Higham Colts player of the match: Jack Carroll.