Pujols hit a two-run homer and reached base five times, Lohse pitched seven innings and the Cardinals beat the Pittsburgh Pirates 9-3 on Tuesday night.
Pujols went 2-for-3 with two walks and also reached on an error after going 3-for-4 in Monday's season-opening 6-4 loss against the Pirates.
Chris Duncan and Yadier Molina also had two-run homers for St. Louis, which pounded out 12 hits against four Pittsburgh pitchers. Joe Thurston and Khalil Greene each had two RBIs. Colby Rasmus went 2-for-4 and scored twice in his major league debut.
"I wouldn't want to pitch against us right now," Lohse said. "Hopefully, we can have more nights like tonight."
Lohse (1-0) allowed three runs, two earned, and five hits to move to 4-0 in six career starts against Pittsburgh.
"It went pretty good for the first one," he said. "I was a little too juiced early. But after that, I felt like I settled in. I didn't have my best stuff in the last couple of innings, but I made it work."
The Cardinals scored all their runs in the first five innings, bouncing back after Monday's difficult loss. With the Pirates down to their last strike, Jack Wilson hit a three-run double to cap a four-run ninth inning off rookie closer Jason Motte as Pittsburgh earned a dramatic victory on Opening Day.
Duncan started Ian Snell's woes when he hit a two-run homer off the foul pole in right with two out in the first. Thurston made it 3-1 an inning later with his first major league hit, an RBI double down the line in right that plated Molina.
After Rasmus singled to right to start the third, Pujols belted a drive over the Pirates' bullpen in left field.
"If you can figure out [how to stop him], you go tell the whole league," Pittsburgh manager John Russell said.
Snell (0-1) lasted just four innings, allowing eight runs, six earned, and nine hits.
"I didn't execute any of my pitches tonight and I paid the price," he said. "I just didn't have location; nothing was working for me."
The crowd of 35,206 was the smallest ever at the new Busch Stadium, which opened in 2006. ... Zach Duke, Pittsburgh's scheduled starter for Wednesday, is 0-4 in his last five starts against St. Louis and has not beaten the Cardinals since Aug. 11, 2006. ... Molina's second-inning triple into the right-field corner was the second triple of his career and first since 2005. ... Pirates 3B Andy LaRoche committed his third error in two games when he dropped Pujols' popup with two out in the third.