"Literally, thank, whatever made it happen, that we've had a chance to see this guy all these years," St. Louis manager Tony La Russa said. "That's how we should all feel."

It was Pujols' 24th multihomer game and first since Aug. 16, 2008, against Cincinnati. He matched his career best for RBIs set Aug. 22, 2006, against the New York Mets.

The All-Star first baseman went 2-for-4 and is batting .429 with three homers and nine RBIs in the team's first six games.

"The best player in the game," Houston manager Cecil Cooper said.

Pujols is just glad to get off to a fast start.

"I feel good," he said. "I don't know about locked in. I just putting my best swing out there and doing what I can to help this ballclub out."

Rick Ankiel and Joe Thurston had three hits apiece for the Cardinals, who finished with 19 hits overall. Adam Wainwright (1-0) pitched five shutout innings.

Roy Oswalt (0-2) had a rare bad outing at Busch Stadium, allowing six runs and nine hits in six innings for the Astros. He had a 1.83 ERA in five previous starts at the new Busch.

"I don't think we've ever done that against the guy," Pujols said. "I'm pretty sure every time he pitched, he's pitched pretty well against us."

St. Louis scored five times in the fifth inning to take a 6-0 lead. Pinch-hitter David Freese doubled in a run before Skip Schumaker walked and Colby Rasmus singled to load the bases for Pujols, who hit Oswalt's first pitch over the wall in left.

"I was ready and I put my best swing on it," Pujols said.

Oswalt felt he had to go after Pujols in that situation.

"With the way we've been scoring, instead of throwing around him to get to the other guys, I was trying to get a double play and leave the game at 2-0," Oswalt said.

The Cardinals added four more against Wesley Wright in the seventh, including Pujols' three-run shot to left.

Wainwright allowed four hits, walked three and struck out four to improve to 6-0 in 13 games against Houston.

"It's amazing how when you score a few runs it makes you feel a little better about your outing," Wainwright said. "But deep down, I know I've got to improve."

Game notes
Astros pitcher Doug Brocail was scheduled to return to Houston on Saturday to be examined by Dr. David Lintner after experiencing discomfort in his right shoulder while pitching Friday. ... St. Louis reliever Jason Motte pitched a scoreless sixth inning and lowered his ERA from 27.00 to 15.43. ... Wandy Rodriguez, scheduled to start for Houston on Sunday, had a 1.11 ERA against St. Louis in 2008. ... Schumaker, who hit .168 against lefties last season (20-for-119), is 4-for-6 against southpaws thus far. ... Houston's Kaz Matsui, who led off the game with a single, has hit safely in all five games.