Kevin Anderson fought back to beat Pablo Carreno Busta in four sets and become South Africa's first US Open singles finalist since 1965.
Anderson, seeded 28th, beat the Spanish 12th seed 4-6 7-5 6-3 6-4 in New York.
He will face world number one Rafael Nadal or 24th seed Juan Martin del Potro in Sunday's final.
More soon.