Already South Korea's first grand slam quarterfinalist, the "Professor" is now the nation's first ever semifinalist after dispatching the controversial figure of Tennys Sandgren 6-4 7-6 (7-5) 6-3 Wednesday at Rod Laver Arena. There has been no stopping Chung in Melbourne -- he upset Germany's Alexander Zverev in the third round and his idol Novak Djokovic in the fourth.
