Jeffcott and Marnoo will fight for the ultimate prize in the Wimmera Mallee Cricket Association's grand final on Saturday.
If the contest is anything like the preliminary finals, spectators will be in for a treat at Warracknabeal's Anzac Park in the league's biggest match of the season.
Marnoo scraped into the final by the skin of their teeth with a one-run victory against minor premiers Donald last week.
Marnoo took the final three wickets while conceding just four runs to upset the favoured Donald, who have sat atop the ladder almost all season.
Jeffcott meanwhile were guided by an impressive knock of 84 from captain Lachlan Jones to a 45-run win against Brim-Kellalac-Sheep Hills.
Jones, who is averaging 57 with the bat this season, will be key for Jeffcott as they try to go back-to-back.
Brylie Cameron is the pick of the batsmen for Marnoo, averaging 36.