Japan and Papua New Guinea set up a rematch of the 2010 title decider after qualifying for Friday's East Asia-Pacific Women's Cricket Championship final.
Defending champions Japan defeated a spirited Vanuatu who, after reaching 42-1 from their first seven overs, collapsed to be all out for 84.
Alvina Chilia top scored for the home side with 24 from 23 balls.
Japan made quick work of the run chase, with Mariko Yamamoto's run-a-ball 40 getting them home with seven wickets to spare.
Coach Chris Ferguson struck a content figure post match and says they will look to keep building pressure in the field and bowling consistently in the final.
That match will be against Papua New Guinea who were clinical in their seven wicket defeat of Samoa.
Tanya Ruma and Ravini Oa caused all sorts of problems for the Nafanua batters, who slumped to 31-5 before being rolled for just 43.
Early wickets to Regina Lili'i and Sinei Mulivai gave Samoa some brief hope with PNG reduced to 17-3, before Varoi Morea and Tanya Ruma combined to guide their team home.
Meanwhile Fiji chased down the Cook Islands total of 86 to finish in fifth place.