Sebastian Korda is into his first clay-court semi-final. Sebastian Korda beat eighth-seeded Yoshihito Nishioka 6-3, 6-3 on Thursday to set up an all-American semi-final against Tommy Paul at the Emilia-Romagna Open. “But it’s my first semifinal on clay and I’m super happy.” Korda next faces the sixth-seeded Paul, who eased past fourth-seeded Jan-Lennard Struff 6-2, 6-4. He’s been playing great, …