The RMC Championships opened in Memphis with two-time winner Andy Roddick beating Richard Berankis of Lithuania 4-6 6-2 6-3.
Roddick, playing for the first time since the Australian Open, had plenty of unforced errors, but produced 23 aces to send him through to the second round, where he'll face Serbia's Janko Tipsarevic.
"It was one of those days where I felt if I made a first serve the point was done, didn't have to do much work after that," Roddick said.
"That gave me a chance. And I played a little bit more aggressive in the third set."
Earlier, No.2 seed Mardy Fish of the USA, overcame a thyroid condition that kept him out of last week's SAP Open to beat Russia's Teymuraz Gabashvili 6-1 7-5.
"I felt a lot better today than I did Friday," Fish said.
"So that's a good sign. Obviously the goal is to try to get to 100 per cent. To be honest, I've felt better each day."
Fish will be looking to repeat his form from last year, where he won two tournaments and reached the finals of three others, resulting in a career-high world ranking of 16.
Those joining him in the second round include American James Blake, who beat Ricardo Melo of Brazil, 6-4 6-3; and 2009 finalist Radek Stepanek of the Czech Republic, who defeated German Benjamin Becker 6-4 6-2.
Croatia's Ivan Dodig, who won his first ATP World Tour event two weeks ago in Croatia, beat Germany's Rainer Schuettler 3-6 6-3 6-4.
Defending champion and fifth-seeded Sam Querrey recorded a 6-7 (7-5) 7-6 (7-5) 6-4 victory over Uzbekistan's Denis Istomin, breaking his three-match winless streak which included first-round exits from Sydney, Melbourne and San Jose.