Agassi, Roddick, Haas Lead Winners at Houston

"I played well considering it was for the first time in a tournament match in three weeks," Roddick said. "I moved pretty well and sneaked out a couple of points."

Haas fell behind 1-3 in the second set before closing it out in straights.

"He started to go for more shots in the second set," Haas said of Vliegen. "He played some good shots. He broke me but I broke back and in the end I hit some pretty good shots to win."

Agassi, stretched to a second-set tiebreak, uncorked his frustration by smashing a racquet after losing the first point of the breaker.

"It was probably a healthy combination of reasons," Agassi said of his racquet smashing. "I was really frustrated through most of the middle of the second set. I had some 0-30 chances and never felt I stepped up."

Also winning on the seeded side was No. 8 Luis Horna (d. Enqvist), while France's Anthony Dupuis (d. (4) Massu, bagel in the second) baked the only seeded upset on the day.

Un-seeds into the second round were four Americans in Jeff Morrison (d. Popp), (WC) James Blake (d. Minar), (LL) Paul Goldstein (d. Vanek) and Kevin Kim (d. (LL) Garcia), Israel's Noam Okun (d. Mello), Spaniard Oscar Hernandez (d. (Q) Bogomolov Jr.), and Ecuador's (Q) Nicolas Lapentti (d. Zib).

No. 5 seed and seemingly perpetually-injured Taylor Dent withdrew from the event with an ankle injury.

In the lone doubles match on the day, wildcards Tres Davis/Roddick defeated Blake/Mardy Fish 6-4, 6-4.

On court Wednesday are (Q) Okun vs. (7) Jurgen "Tuna" Melzer, (1) Roddick vs. Ginepri in an all-American, (3) Haas vs. Jeff "Baby Krajicek" Morrison, and (LL) Goldstein vs. (8) Luis "Me So" Horna.