Roddick, seeded 10th in Shanghai, defeated Yen-Hsun Lu 6-2, 3-6, 6-2 but it was probably tougher than Roddick expected. Still, he won 70 percent of the points on serve and lost his serve just once.
He also had a pair of service breaks in both the first and third sets to advance.
No. 16-seeded Fernando Verdasco beat Li Zhe 6-2, 6-2 in the only other match Monday involving a seeded player. Verdasco saved the only break point he faced and finished off four break changes in eight Li service games.
Guillermo Garcia-Lopez topped Somdev Devvarman 6-4, 6-3 and earned a second-round slot opposite top-seeded Rafael Nadal. Garcia-Lopez landed just 39 percent of his first serves but won nearly two-thirds of the points on serve.
Nadal and the other top eight seeds have first-round byes in Shanghai.
David Nalbandian was a 7-5, 6-4 winner over Ernests Gulbis and Juan Carlos Ferrero got by Mikhail Youzhny 7-6 (7-4), 6-4. In other matches on Nadal's side of the bracket, Grigor Dimitrov took out Marsel Ilhan 2-6, 6-1, 6-4 and Tommy Robredo edged past Stephane Bohli 7-6 (7-3), 7-6 (7-4).