Frenchman Gael Monfils posted an opening-round victory on Monday over American James Blake at the $455,000 U.S. Men's Clay Court Championship.
In a battle of former top-10 players, Monfils defeated Blake 7-6 (7-5), 7-5 at River Oaks Country Club.
Blake was the runner-up here in 2008.
Also on Day 1, American wild card Rhyne Williams handled Argentine Guido Pella 7-5, 7-5 and fellow American Tim Smyczek cruised past Frenchman Josselin Ouanna 6-1, 6-2.
This week's top seeds are Spanish star Nicolas Almagro, resurgent German Tommy Haas and reigning champion Juan Monaco, who beat towering American John Isner in last year's Houston finale. Haas captured this event in 2004.
This week's winner will collect $82,300.