Top-seeded Nicolas Almagro of Spain advanced to the U.S. Men's Clay Court semifinals Friday, using service breaks at the end of each set to beat Italy's Paolo Lorenzo 6-4, 6-4.
Almagro, ranked 12th in the world, will face Rhyne Williams, the American wild card who rallied from an 0-3 deficit in the third set to beat Spain's Ruben Ramirez Hidalgo.
In the other quarterfinals, third-seeded Juan Monaco of Argentina faced American Robby Ginepri, and fifth-seeded John Isner of the United States was set to play Lithuania's Ricardas Berankis.
Almagro and Lorenzo stayed on serve in the first set until the final game, when Lorenzo double-faulted to start the game and lost it at the first break point when his drop shot fell short.
They traded breaks in the second set and Almagro went into the final game with a 5-4 lead. Almagro won at the first match point with a forehand winner that left his opponent flat-footed.
The 22-year-old Williams won a tight first set after sailing through a runaway tiebreaker, but he was victimized by his serve in the second set. He didn't rally until he held in the fourth game of the final set and broke Hidalgo at the third break point in the fifth game.
Williams held and broke Hidalgo again in the seventh game when Hidalgo hit consecutive double-faults to end the game. Hidalgo escaped two match points to hold his serve in the ninth game but Williams served a love final game, ending it with consecutive aces.