Juan Monaco beat Kevin Anderson 7-6 (4), 7-5 to advance to the semifinals of the U.S. Men's Clay Court Championship.
In the second afternoon quarterfinal on Friday at River Oaks Country Club, Houston resident Michael Russell beat 19-year-old Ryan Harrison 6-1, 5-7, 6-3.
The 28-year-old Monaco improved to 9-2 on clay and reached his third semifinal this year. He won on the clay in Vina del Mar in February and lost to top-ranked Novak Djokovic in the semifinals in Miami last month.
Monaco broke Anderson's serve to take a 6-5 lead in the second set, and Anderson fought off two match points before Monaco finished him off.
The 33-year-old Russell, a qualifier, converted 39 of 55 first serves to earn his first career semifinal berth.