Sam Querrey, Jack Sock set up all-American final in US Men's Clay Court Championship

Sam Querrey returns a shot to Fernando Verdasco, of Spain, in a semifinal tennis match at the U.S. Men's Clay Court Championship, Saturday, April 11, 2015, in Houston. (AP Photo/Pat Sullivan) (The Associated Press)

Sam Querrey of the United States returns a shot to Fernando Verdasco of Spain in a semifinal match at the U.S. Men's Clay Court Championship Saturday, April 11, 2015, in Houston. (AP Photo/Pat Sullivan) (The Associated Press)

Sam Querrey and Jack Sock set up the first all-American final in a dozen years in the U.S. Men's Clay Court Championship.

The eighth-seeded Querrey dominated on his crushing serve in the rain-interrupted third set Saturday to upset defending champion Fernando Verdasco of Spain 7-5, 2-6, 6-4. Sock knocked off third-seeded Kevin Anderson of South Africa 7-6 (3), 6-3 to advance to his first ATP World Tour final.

The last time two U.S. players squared off in the final, Andre Agassi beat Andy Roddick in 2003. The Querrey-Sock match will be the first showdown between two Americans anywhere in an ATP Tour final since Mardy Fish topped John Isner in Atlanta in July 2011.