Defending champion Andy Roddick fought to defeat qualifier Paul Goldstein 7-5, 6-4 on Wednesday to reach the quarter-finals of the $380,000 U.S. Clay Court Championships.

Roddick, the second seed, was down a service break in both sets before defeating Goldstein in a second round match at the Westside Tennis Club.

Roddick, winner at Houston in 2002 and 2001, will play Fernando Meligeni in the quarter-finals on Friday. The Brazilian claycourt specialist defeated Vincent Spadea, the fifth seed, 4-6, 7-6 (8-6), 6-3.

Ranked 193rd in the world, Goldstein was leading 4-1 in the first set when Roddick recovered with a service break in the seventh game and levelled the contest 4-4. He broke again in the 11th game, held service and won the set.

"I rely a lot on my serve," Roddick said.

"It was tough today with the wind. On one side of the court, I was able to use spin and, on the other side, it just sat up. The wind does not help my game."

In the second set, Goldstein was serving at 4-2 and 40-30 when he missed an open court volley, allowing Roddick back into the game. Roddick won the final four games.

"I gave myself a lot of opportunities," Goldstein said.

"I'm disappointed that I didn't take advantage of those opportunities."