Steve Johnson has beaten top seed Jack Sock 4-6 6-4 6-3 in an all-American semi-final in the US Men's Clay Court Championship in Houston.
Fourth-seeded Johnson won his lone ATP Tour title last year on grass at Nottingham in England.
He will face eighth-seeded Thomaz Bellucci of Brazil, a 5-7 6-4 6-2 winner over American Ernesto Escobedo.
Sock won the 2015 event at Forest Oaks for the first of his three tour titles, and finished second last year.
He's the highest-ranked US player at No.16.
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Bellucci has won four tour events, all on clay.
Making his first appearance in the only ATP event played on clay in North America, he won his fourth three-set match in four days.
It marked the first time in 27 years, going back to David Wheaton in 1990, that a player needed 12 sets to reach the final.
