SAN DIEGO — Yu Darvish began to look like his normal self on the mound early in the second inning of Japan's game against South Korea in the World Baseball Classic.

By then, it was already much too late.

South Korea pounced on Darvish in the first and pitcher Bong Jung Keun had another quality start as South Korea reached the semifinals of the WBC with a 4-1 win over Japan on Tuesday night at PETCO Park.