France's Gael Monfils booked his place in the second round of the US Men's Clay Court Championship in Houston with a 7-6 (7-5) 7-5 victory over James Blake.
The 26-year-old rallied from a break down in both sets to defeat the American, a finalist in Houston in 2008, in one hour and 47 minutes.
Monfils, who won only one of his 10 break points in the first set, now faces top-seed Nicolas Almagro of Spain.
The pair are both making their debuts in the event and have each won twice in their previous four meetings.
Blake's fellow Americans Rhyne Williams and Tim Smyczek both enjoyed first-round victories, beating Argentina's Guido Pella 7-5 7-5 and Frenchman Josselin Ouanna 6-2 6-1 respectively.
American Robby Ginepri and Bradley Klahn, Austrian Gerald Melzer and Facundo Arguello of Argentina sealed the four main-draw places available through qualifying.
Melzer, the younger brother of Davis Cup stalwart Jurgen, upset Croatia's Ivo Karlovic, the 2007 champion, in straight sets.
Britain's Jamie Murray reached the last 16 of the doubles competition along with Australian partner John Peers with a 6-3 1-6 10-4 victory over Nicholas Monroe and Simon Stadler.