Andy Roddick began his bid to return to the world's top 10 by crushing Ramon Delgado 6-3, 6-2 to reach the RCA Championships third round on Tuesday.
The American, Indianapolis champion in 2003 and 2004, dropped to 11th in the rankings following his third-round defeat at Wimbledon, the first time the 2003 US Open champion has been out of the top 10 since 2002.
Mark Philippoussis, winner of last week's Newport tournament on grass, lost 6-4, 7-5 to Korea's Hyung-Taik Lee in the first round while Wayne Arthurs beat Israeli Harel Levy 6-3, 7-5.
Philippoussis, fresh from winning his first title since 2003, was unable to adjust to the change of surface.
"I was struggling in the conditions, but I felt okay," he told reporters. "I'm a little disappointed but it was a good chance to get more practice and get match tough."
Roddick fired eight aces against the Paraguayan, including one on match point, to improve his tournament record to 13-1 on his favourite hardcourt surface.
"I feel really motivated, I can't wait to get out there and play," Roddick told reporters. "I played solid throughout, I wasn't defensive at all. I accomplished a lot of things that I wanted to."
Compatriot Robby Ginepri opened his title defence with a battling 4-6, 7-5, 7-5 victory over Colombia's Alejandro Falla.
The fourth-seeded American double-faulted on match point before serving out three games later to complete victory in over two hours.
"I can't remember the last time I was this nervous before a match," Ginepri told reporters. "Somehow I snuck this one out. I was absolutely exhausted, and a lot of that was nerves."
Chile's Fernando Gonzalez, the third seed, faced little opposition from the 200th-ranked Sam Querrey, booking his third-round place with a 6-3, 6-4 win over the American wild card.
The South American world number 16 needed just 67 minutes to end the challenge of the 18-year-old in steaming temperatures and humidity.