Argentine fourth seed Juan Monaco edged South African fifth seed Kevin Anderson 7-6 (7-4) 7-5 on Friday to reach the semi-finals of the $US442,500 ($A425,350) ATP US Men’s Clay Court Championships.
The South American will play on Saturday for a berth in Sunday’s final against qualifier Michael Russell, who outlasted Ryan Harrison 6-1 5-7 6-3 in an all-American quarter-final.
Monaco, ranked 16th, won his fourth career ATP title, and first since 2007, last February at Vina del Mar and reached the semi-finals last month at Miami, losing to eventual winner and World No.1 Novak Djokovic.
Anderson, ranked 33rd, was denied a chance for his second title in as many months after taking his second career ATP crown last month at Delray Beach, Florida.
Russell, a 33-year-old hometown hero, reached his first career ATP semi-final by holding off Harrison, a 19-year-old who was the youngest qualifier at Houston since Andy Roddick won the 2002 title at age 19.
In later matches, US second seed and World No.10 John Isner faces defending champion Ryan Sweeting in another all-American quarter-final and sixth seed Carlos Berlocq of Argentina meets Spanish third seed Feliciano Lopez.