MEMPHIS, Feb. 25 (UPI) -- Second-seeded American James Blake withdrew with a sore knee Monday from the Regions Morgan Keegan Championships.
Third-seeded German Tommy Haas, the defending champion, advanced in the first round with a 6-3, 6-2 victory over Argentine Diego Hartfield.
Haas, a two-time defending champ, also won in 1999. He beat Andy Roddick in last year's final.
Seventh-seeded Jurgen Melzer of Austria had a tough match before beating American John Isner 6-7 (8-10), 6-3, 7-6 (7-4).
In other first-round action, Australian Chris Guccione defeated American Robert Kendrick 7-6 (8-6), 7-6 (7-5); Frenchman Florent Serra beat Brazil's Marcos Daniel 6-1, 6-2; Swede Jonas Bjorkman beat Chile's Paul Capdeville 6-3, 6-1; and Colombian Alejandro Falla defeated Israel's Dudi Sela, 6-4, 6-2.
Roddick, last week's champion in San Jose, is this week's top seed.
