Former world number one Andy Roddick won his first match since Wimbledon when he enjoyed a regulation straight-sets victory over Edouard Roger-Vasselin at the Winston-Salem Open.
The top seed fired 11 aces and broke his opponent's serve three times to dismiss the Frenchman 6-2 6-4.
Since exiting Wimbledon in the third round, the 28-year-old lost to David Ferrer in the Davis Cup before being sidelined with an abdominal strain.
He then lost to Philipp Kohlschreiber in the first round in Cincinnati last week.
The American will now face number 15 seed Santiago Giraldo who beat Blaz Kavcic 6-2 6-3.
Third seed Alexandr Dolgopolov beat Argentinian Carlos Berlocq 6-4 6-4 while fourth seed John Isner served up 17 aces in a 7-6 (7/3) 6-2 victory and Nikolay Davydenko, seeded fifth, eased through 6-2 6-2 against Michael Russell.
There were also wins for seeds Juan Monaco, Sergiy Stakhovsky, Robin Haase, Jarkko Nieminen and Grigor Dimitrov.
However, seeds Dmitry Tursunov, Pablo Andujar and Igor Kunitsyn all went out.