The United States team said its "next man up" philosophy has powered it during the Premier 12.
The Americans will play for the title on Saturday because the next man up kept getting on base during the fourth inning.
Zeke Spruill controlled things on the mound in a surprise start and the U.S. scored five runs in the fourth inning to overcome a one-run deficit and advance to the Premier 12 final with a 6-1 victory over Mexico on Friday night at Tokyo Dome.