American Sam Querrey was a first-round winner while his compatriot James Blake was ousted at the U.S. Men's Clay Court Championship on Monday.

Querrey, the 2010 Houston runner-up, posted an easy 6-1, 6-4 victory over Frenchman Eric Prodon. He fired six aces and never faced a break point as he won in under one hour at the River Oaks Country Club.

Blake, meanwhile, was subdued by sixth-seeded Argentine Carlos Berlocq in 6-4, 2-6, 6-1 fashion. Blake was a runner-up here in 2008

Finally, German Bjorn Phau advanced 6-1, 3-0 when Argentine Diego Junquiera retired.

This week's top seeds are American stars Mardy Fish and John Isner, who propelled the United States past host France with a victory over Jo-Wilfried Tsonga in this past weekend's Davis Cup quarterfinal showdown at the Monte Carlo Country Club.

Fish was the Houston champion in 2006.

American Ryan Sweeting was a surprise winner here a year ago when he beat Japan's Kei Nishikori in the finale.

The winner of this $442,500 event will take home $79,880.