Roddick was given a fright by fellow American Fish

The top seed took two hours and 15 minutes to see off determined fellow American Mardy Fish in three tight sets for a 6-3 6-7 (5-7) 7-6 (7-2) win.

But fourth seed Robby Ginepri fell to Russian Dimitry Tursunov 7-5 7-6 (7-4) and fifth-ranked James Blake was bundled out by Kristof Vliegen 6-4 6-4.

Seventh seed Max Mirnyi was thrashed 6-0 6-1 by Robin Soderling of Sweden.

Roddick admitted he had been fortunate to edge past Fish in a match which contained only one break of serve.

"He played better than I did for the majority of the match," he said after booking a second-round clash with Australian Wayne Arthurs.

"I thought he served pretty well and I didn't have much of a chance to break.

"He probably had more chances than I did. He just made a couple of sloppy errors in the third-set tiebreaker."