The United States is looking to defend its 2007 Davis Cup title but was paired with Austria, which opted to play on clay, which is the U.S. team's least-favorite surface.
The ploy seemed to work Friday with Roddick pushed to five sets and more than four hours of play before defeating Jurgen Melzer, 6-4, 4-6, 6-3, 6-7 (4-7), 6-3. Melzer broke Roddick's serve in the first game of the fifth set but Roddick answered by taking four consecutive games and control of the match.
Blake dropped his first set and battled through the second before taking over and finishing off Stefan Koubek, 5-7, 7-5, 6-2, 6-2.
The Americans can wrap up a trip to the Davis Cup second round with a victory by the world No. 1 doubles team of twins Bob and Mike Bryan -- 13-1 in Davis Cup play -- over Austrians Melzer and Julian Knowle.
If that doesn't decide the series, it will be determined by Sunday's reverse singles in which Roddick is to meet Koubek and Blake is to go against Melzer.