Mazars Grange bowled out Capital rivals Carlton for just 36 runs to progress to the Murgitroyd Masterton final.
The bemused Carlton batting line-up had no answers at Raeburn Place and Grange eventually went on to win the Twenty20 match by ten wickets.
Grange now go into Friday’s final at Grange Loan (6pm) and will start as favourites against Baillie Gifford ESCA Championship side Stuart&Stuart Penicuik.
With Penicuik already safely through, Grange and Carlton met to decide their final opponents and, from the first over, the visitors were in danger.
Gordon Goudie took two early wickets as Carlton were reduced to 16-4 from six overs and then Andrew Brock, Harris Aslam and young Robbie McCallum – with his first wicket for the first XI – got in on the act.
When Avinash Yadav took the last wicket, Carlton had mustered just 36.
In reply, Grange openers Ryan Flannigan and Nick Farrar led them to victory.