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.

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.