Michael Tucker's two-run pinch-hit homer snapped a sixth-inning tie as the U.S. Olympic team beat the Japanese national team, 6-2, at St. Louis.
Jason Moler of Cal State Fullerton also homered and doubled for Team USA, and Chris Roberts had a two-run single.
Rick Greene (1-0) pitched an inning of scoreless relief for Team USA, which is 11-3 on a 30-game pre-Olympic Tour.
The game was shortened to six innings due to time constraints on the USA's travel itinerary.
Team USA was 5-1 in a six-game series against Japan. Team USA next will play a three-game series in Cuba.