Lidge, in missing a chance to protect the Astros' 5-4 lead, was tagged with the loss and his sixth blown save of the season.
The inning began when Lidge yielded a leadoff hit to John Rodriguez and pinch-runner Skip Schumaker advanced to second on Jose Vizcaino's sacrifice bunt. Preston Wilson struck out, but Lidge hit Scott Spiezio with a first-pitch slider, bringing to the plate Pujols, the famous nemesis of the Houston closer.
"Obviously, the guy's a great hitter," Lidge said. "I made some pitches inside, and the last one, he got, too. He's a strong hitter, and he's a very clutch hitter. Unfortunately, he got that one, and it's too bad. I feel bad about it for our team. We did a great job coming back tonight and getting some runs."
Pujols' double bounced in the corner and looked like it got away from Jason Lane, a late-game defensive replacement in left field. After a few bounces, it was obvious that Spiezio would have no problem scoring from first.
"The ball was hit on the edge of the grass of the warning track," Lane said. "I felt like the way the corner plays tricky, I felt like I couldn't go back and let it get in the corner and carom around. Spiezio would probably score. I tried to cut it off, and it hit right on the warning track and it kicked left, right into the corner."
Pujols, seemingly undeterred under any kind of pressure, was not fazed by the notion that he was down to his last strike.
"When you have a guy like that, one of the best closers in the league, you don't want to think about anything," said Pujols, who was 1-for-10 in the regular season against Lidge heading into the at-bat. "All you want to do is just hopefully let him make a mistake, and you take advantage. Those guys, they have a great bullpen. When you face those guys out in the bullpen, you don't want to think too much."
Pujols' hit sent the Cardinals to their division-leading 77th win. The Astros are now seven games back in the National League Central and 4 1/2 back in the Wild Card race.
For a while, a back-and-forth contest looked like it was going to end in the Astros' favor. The Astros struck first, behind Mike Lamb's solo homer off Jeff Weaver in the opening frame.
The Cardinals answered with two in the third, behind Wilson's two-run homer off Andy Pettitte. Houston regained the lead in the fourth after Orlando Palmeiro came through with a pinch-hit, two-run single up the middle off Weaver, but St. Louis tied it in the bottom of that frame when Yadier Molina singled to drive in Juan Encarnacion, who had tripled off Dave Borkowski.
Chris Burke knocked a 406-foot, two-run homer off Weaver in the sixth, giving the lead back to the Astros.
Pettitte departed the game in the third inning with a left elbow flexor muscle strain, and the bullpen combined for 5 1/3 innings during which it allowed two runs, until the ninth inning.
"We put ourselves in that predicament by allowing Albert to come to the plate," catcher Brad Ausmus said. "He's the guy we don't want to come to the plate unless we've got a base open. But in terms of the pitch to Albert, Brad made good pitches. He's a tough guy to get in on and a tough guy to break his bat. Brad was able to do that. Unfortunately, it found a spot to land where we didn't have any defenders. Sometimes, you've got to get a little lucky when you're good, and he's obviously very good."
Said Lidge: "It's been a frustrating year. It seems like stuff like that is happening this year, and thinking about the pitch, I was able to get it in there, and he broke his bat. But he was able to put it in a place where we couldn't get to it, and it ends up being a two-run double. It's very frustrating."