Roddick topped Rik De Vroest of Italy, 6-4, 6-4; and Gonzalez beat former world No. 1 Marat Safin, 6-4, 6-2.
Elsewhere, No. 5 Andre Agassi beat George Bastl of Switzerland, 6-7 (4-7), 6-2, 6-1; sixth-seeded Tommy Haas of Germany topped Paul Capdeville of Chile, 6-3, 4-6, 6-1; and Paul Goldstein, who stunned second-seeded Lleyton Hewitt of Australia on Tuesday; beat Igor Kunitsyn of Russia, 6-4, 6-4.
It was Roddick's first match since hiring the legendary Jimmy Connors as his new coach.