Tokyo, Japan - The US defeated South Korea 7-2 in the Olympic baseball semi-final on Thursday, and will face hosts Japan for gold on Saturday.

The South Koreans lost 5-2 to Japan in the first semi-final on Wednesday, but had another chance against the Americans, who had beaten the Dominican Republic in the round two repêchage.

The US took the lead in the second inning, with Mark Kolozsvary making it to home plate after good work by Jack Lopez, who plays for the Boston Red Sox.

Jamie Westbrook's home run in the bottom of the fourth gave the US breathing space, with 2008 champions the Koreans finally challenging the scorers in the fifth inning.

Totaling five runs in a frantic sixth inning in Yokohama had the US cruising, with South Korea's scoring at the top of the seventh making little difference.

The Dominicans now play the Koreans in the bronze medal game on Saturday, which precedes the gold medal final.

Baseball last took place in the Olympics in 2008 and has returned as a probable one-off for Tokyo. Japan won the women's softball gold last week.