Fourth seed Benjamin Becker suffered an opening-round defeat to Brendan Evans in Campbell's Hall Of Fame Tennis Championships in Newport.
The American came through 7-6 (7/5) 3-6 7-5 against his German opponent.
His compatriot Robby Ginepri is also through to round two after beating Spain's Santiago Ventura 6-2 1-6 6-4.
Taylor Dent enjoyed a smoother passage as the big-serving American thrashed Marcos Daniel of Brazil 6-2 6-1.
Jesse Levine, Daniel Brands and Prakash Amritraj were also first-round winners.