Jamaica took yet another giant step towards an unprecedented fifth successive first class title when they brushed aside a fragile Guyana by 133 runs with a day to spare.
Captained by out-of-favour West Indies left-arm spinner Nikita Miller, Jamaica bundled out Guyana for a meagre 126, after they had been set a target of 260 to win.
Miller, who has not played for West Indies since the World Cup last year March, claimed four for 28, to finish with match figures of seven for 44.
Guyana had no answer to the rampant Jamaicans, who marched to their seventh straight win in the competition.
They will now meet Barbados in the final next weekend after the Barbadians crushed Trinidad and Tobago by 227 runs in Port of Spain.
It was left up to captain Tamar Lambert again to marshall the middle and lower order, and he stroked 37 from 138 balls with three fours, before being eighth out.
He put on 35 for the fifth wicket with David Bernard Jr who scored 16.
In their turn at the crease, Guyana offered precious little resistance and quickly plunged to 30 for three.
Once Deonarine was lbw to leg-spinner Odean Brown (3-42), the floodgates opened again and Guyana lost their last seven wickets for 58 runs.