The return of baseball to the Olympic stage has not disappointed for Team USA.
The excitement continued as the United States won Group B with a 4-2 victory over defending Olympic champions South Korea on Saturday at the Yokohama Stadium in Tokyo.
The U.S. will now face host nation Japan in the next stage in a battle of group winners with first pitch at 6 a.m. ET on Monday.
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The U.S. and South Korea entered Saturday's contest with 1-0 records in the Olympics after defeating Israel in their series openers.
South Korea scored just three at-bats into the game with Hyun-soo Kim hitting an RBI fielder's choice off of Team USA starter Nick Martinez. That was all the damage South Korea would do against Martinez, though. The former Texas Rangers pitcher posted a final line of five innings, four hits allowed, one earned run and nine strikeouts on 87 pitches.
The Team USA offense was stifled by South Korean starter Young-pyo Ko through three innings before Boston Red Sox prospect Triston Casas belted a two-run homer to take the lead in the fourth inning.
Team USA extended its lead in the fifth inning with four straight two-out hits. Nick Allen drilled a solo homer, while Tyler Austin plated Jamie Westbrook on an RBI single.
South Korea got the tying run to the plate in the top of the ninth, but Team USA reliever David Robertson retired the side with a sacrifice fly, strikeout and a spectacular play at third base from Jack Lopez to end the game.
With Japan up next, the United States has some work to do if it wants to win its second gold medal since the Olympic inclusion of baseball at the 1992 Barcelona Games. The U.S. has medaled three times overall in five Games, earning two bronze medals.