Giants starter Barry Zito encountered trouble as Ty Wigginton opened the Astros' sixth with an infield single. It was a grounder up the middle that shortstop Omar Vizquel corralled before performing a graceful 360-degree spin to throw to first base, but his peg was an instant late. Mark Loretta walked and Miguel Tejada hit a pop fly that fell among center fielder Aaron Rowand, right fielder Randy Winn and second baseman Emmanuel Burriss. That single loaded the bases.
Zito then walked Lance Berkman to force in the tying run before Geoff Blum's sacrifice fly put Houston ahead and advanced the remaining runners to second and third. An intentional walk to Hunter Pence reloaded the bases before Reggie Abercrombie lifted a sacrifice fly. Zito hit Humberto Quintero with a pitch and walked opposing pitcher Randy Wolf on a 3-2 delivery to force in a run.
In came right-hander Billy Sadler, who hit the first two batters he faced, Wigginton and Loretta, to push across two more runs.
Dissecting the inning, Zito criticized himself for walking Loretta and hitting Quintero.
"Those were the difference-makers right there," he said.
Zito didn't second-guess himself for walking the formidable Berkman, who hit a grand slam in Houston's uprising Tuesday.
"I didn't want to give in to Berkman," Zito said. "I wasn't really concerned with that walk because, as we saw last night, he can make it four runs."
Nor did Zito lament the charmed hits by Wigginton and Tejada.
"You can't do anything about bloop hits or infield hits," he said, then repeated, "It's on me for walking Loretta."
But manager Bruce Bochy believed that the hits precipitated the Giants' downfall.
"We just self-destructed at that point," he said.
Zito had little to say about his final self-destructive act, which was walking Wolf.
"I just lost my aggressiveness," he said. Against a pitcher batting .140? "I don't know. I just did," he said.
The Giants matched a season-worst by falling 19 games under .500, yet some positive nuggets could be mined from their performance.
Zito blanked Houston on two hits before the telling sixth. "He was locked in," Bochy said.
Winn doubled twice, and Rowand hit two balls that might have been home runs in other circumstances. His first-inning flyout would have landed in the Crawford Boxes had it traveled a few feet to the left, and his seventh-inning drive to center was hauled in by Abercrombie at the foot of Tal's Hill, several paces in front of the 436-foot marker.
Third baseman Ryan Rohlinger, promoted earlier in the day from Double-A Connecticut, became the 13th Giants rookie to make his Major League debut this season. One of three Minor Leaguers to join the Giants -- catcher-first baseman Pablo Sandoval and first baseman Travis Ishikawa were the others -- Rohlinger committed two errors but also stroked a seventh-inning RBI single.
"Those kids are going to be a little nervous," Bochy said. "That's to be expected."
Finally, catcher Bengie Molina maintained his cool despite being hit by a pitch for the third consecutive night. By all indications, the sixth-inning plunkings by Zito and Sadler weren't meant as retaliation.
"It's part of the game, I guess," Molina said. "I think they were trying to pitch me inside and balls got away. They don't have any reason to throw at me, so I'm not sweating that."
Bochy was less forgiving.
"He's been hit enough," Bochy said. "That's all I have to say."