Cuba's Hector Olivera is congratulated by Michel Enriquez
Defending champions Cuba crushed the United States 10-2 to reach the Olympics baseball final.
They will meet South Korea, who fought back from an early 2-0 deficit to beat Japan 6-2.
Cuba - who beat the US in group play last week - pounded 14 hits, beginning with three in the third inning to take a 2-0 lead.
Earlier Japan took an early lead after runs from Tsuyosh Nishioka, but could not keep their momentum going.
And South Korea took advantage, with Lee Seung-yuop hitting a crucial two-run home run in the eighth inning and Kang Min-ho all but sealing it.