Zimbabwe snuck into the tri-series final with a Duckworth-Lewis Method victory over West Indies in Bulawayo on Friday, in which they were indebted to a 91-run rear-guard between Sikandar Raza and Tendai Chisoro.
West Indies looked to have victory in the bag when they reduced Zimbabwe to 127-8 in a match that had been cut to 49 overs per side.
Devendra Bishoo and Ashley Nurse took three wickets apiece, but a stirring partnership between Chisoro - who hit a career-best 42 - and Raza (76 not out) would ultimately condemn West Indies to another narrow defeat after going down by a single run to Sri Lanka last time out.
Series hosts Zimbabwe and Sri Lanka will now contest the final, back at the Queens Sports Club on Sunday.
West Indies were stranded on 124-5 when heavy rain curtailed play. With five more runs on the board, or one fewer wicket down, they would have won.
Johnson Charles was out for a first-ball duck in the first over and opening partner Evin Lewis (9) also fell cheaply, failing to back up his hundred against Sri Lanka.
Raza and Chisoro were the opening bowlers as West Indies stumbled out of the gate, the duo combining to dominate both sides of the game.
Jonathan Carter (43 not out) was the only Windies batsman to show any patience and lasting power, but his efforts were in vain once the rain came.