Top seed Nicolas Almagro and defending champion Juan Monaco each secured berths in the semifinals at the U.S. Men's Clay Court Championship on Friday.

Almagro got past seventh-seeded Italian Paolo Lorenzi in 6-4, 6-4 fashion at River Oaks Country Club. The sweet-swinging Spanish star popped nine aces in the 1-hour, 21-minute victory.

Up next for Almagro will be American wild card Rhyne Williams, who reached his first-ever ATP semifinal by outlasting Spaniard Ruben Ramirez Hidalgo 7-6 (7-1), 1-6, 6-4 in just under 2 1/2 hours on Day 5.

Williams is a 22-year-old from Knoxville, Tenn., and was a two-time All- America at the University of Tennessee.

Monaco, who defeated John Isner in last year's Houston finale, had little trouble with Robby Ginepri in Friday's quarters. The third-seeded Argentine disposed of his American foe 6-1, 6-0 in a match that took just 56 minutes to complete.

Isner set up a rematch with Monaco by topping Ricardas Berankis in three sets, with the towering American outlasting the Lithuanian by a 6-3, 3-6, 6-3 score.

The 2013 Houston champ will collect $82,300. This marks the lone ATP clay- court event in the U.S.