St Just were beaten by Ealing by seven wickets in the semi-finals of the national Twenty20 club championships at the County Ground, Chelmsford.
The Cornish side posted a disappointing 108-6, Gary Thomas top-scoring with 22 and Mark George hitting 18.
In reply Ealing cruised to victory in just 16.2 overs.
Opener Chris Peploe scored 36 while Mylo Wilkin (20) and Patrick Fallis (28) put on an unbeaten fourth-wicket stand of 55 to take the win.
It is the third time that St Just have made the televised stages of the national clubs championship, but they have never got past the semi-final stage.
They made the last four of the 45 over format event in 2006 and 2007.