The right-hander was powerful but imprecise early, throwing 56 pitches through three innings. At that rate, Cain appeared bound for either a premature exit or a late-inning meltdown -- like the one he endured last Thursday at Pittsburgh, when he took a 4-2 lead into the seventh inning and yielded three runs in a Giants loss.
Cain suddenly became as economical as a coupon-clipper, negotiating the fourth through seventh innings on 36 pitches. He needed 22 pitches to get out of the eighth inning, which included Carlos Lee's home run. But that was preceded by a swinging strikeout of Lance Berkman, who's batting .600 (27-for-45) during a 12-game hitting streak. Subduing Berkman reflected Cain's ability to maintain his strength.
Brian Wilson pitched a perfect ninth inning to notch his National League-high 12th save, ensuring that Cain's effort wouldn't be wasted.
Cain's turnaround began not with his impressive fastball, but actually his curveball.
"Sometimes when the fastball's not there, you have to go to your 'off' pitch," catcher Bengie Molina said. "I think once we started throwing curveballs, his body was aligned. Once he started feeling it, it was all over."
Cain's mind felt right from the outset.
"I know the last game he was frustrated because we had a lead and it slipped away," said Giants manager Bruce Bochy, referring to the Pittsburgh setback. "But today he looked really determined to get it done. He just had that look."
Cain (2-3) acknowledged that he stayed focused against the Astros, who had won four games in a row and nine of their previous 10.
"In the last outing, I felt like I didn't stay locked in in the seventh," he said. "I got in a situation where I was like, 'I've got two runs to give,' and that got me in trouble, instead of treating it like a 0-0 or 1-0 game. So I tried to keep that mentality."
Insufficient support has followed Cain since the start of last season. The Giants have scored no more than one run for him in 17 of 41 starts since then. However, Cain's also 21-6 when San Francisco amasses at least three runs for him. The Giants reached that magic number in the first inning, heralding a successful evening.
Lewis tripled to open the Giants' first against Astros starter Brandon Backe (2-5). Vizquel delivered the rally's centerpiece, hitting a weak but well-placed fly to shallow center field and victimizing the scattered Astros defenders to collect an RBI double. Randy Winn doubled home Vizquel before advancing on Molina's fly ball and scoring on a passed ball.
Afterward, the Giants were still marveling at Vizquel's baserunning.
"Our energy level has to be 120 percent every day. Watching that happen, it's always great," Molina said.
Many players would have stopped at first base, but not the canny 41-year-old.
"The first baseman was the cutoff man, and the second baseman and shortstop went for the ball," Vizquel said. "When the center fielder dropped his head, I felt like I had a pretty good chance to make it."
That was it for the Giants at the plate until the fifth inning, when Cain led off with his second homer of the season and the fourth of his career.
"I guess if you get your 245-pound body into it, you can get it to move a little bit," Cain said.
Some drama remained, as Lewis batted in the seventh needing a homer to hit for the cycle -- a feat he achieved a year ago to the day at Colorado. After flying out to medium-deep center field against Houston reliever Tim Byrdak, Lewis readily admitted that he wanted another piece of history.
"I was thinking about the home run more than anything," Lewis said. "I was like, 'Man, this is going to be hard.' And I knew it was going to be harder when they put the lefty [Byrdak] in there."
It was one of the few times the Giants fell short all night.