Thailand's Paradorn Srichaphan was pushed to a first-set tiebreaker before cruising past Frenchman Thierry Ascione 7-6, 6-1 in the second round of the RCA Championships in Indianapolis on Tuesday.
The fourth-seeded Paradorn, who lost to America's Andy Roddick in the final here last year, got stronger as the match wore on to win his first career meeting with Ascione.
The top 16 seeds received byes into the second round at this event.
Ivan Ljubicic of Croatia was the only other seeded player in action and the number 10 recorded an easy 6-2, 6-3 victory over American Rajeev Ram.
There were also 13 first-round matches, among which Australia's Wayne Arthurs dropped a 7-6, 6-1 decision to Rik De Voest of South Africa and Armenia's Sargis Sargsian was upset 6-3, 6-3 by Gregory Carraz of France.
Roddick is the tournament's number one seed and he begins the defence of his title on Wednesday against Michel Kratochvil of Switzerland, who eliminated Jan Vacek of the Czech Republic 6-2, 5-7, 6-3.