Pujols made them pay by lining two-run homers in his first two at-bats Sunday, doing most of the damage against Kevin Slowey in a 5-3 victory on Saturday.
His crucial ninth-inning strikeout against Joe Nathan in a two-run loss the previous night was on his mind.
"Things like that are going to happen in this game so you can get better at it," Pujols said. "Sometimes I'm going to miss those pitches and someday I'm going to have a good day like I did today."
Pujols leads the majors with 28 homers and 74 RBIs in 76 games after his 29th career multihomer game, sixth this season and second in six days. Both homers came off Slowey (10-3), whose bid to take the major league lead in victories was a bust, and Pujols' second long ball put the Cardinals ahead 5-3 in the third.
"I don't know if looking back you should say we should have walked him," Slowey said. "For me, looking back, I need make a better pitch in both situations."
Josh Kinney (1-0) allowed two hits in 1 2/3 innings of relief for his first career victory and struck out feebly in his first career at-bat after manager Tony La Russa elected not to use an early pinch hitter with two outs, the bases loaded and Slowey on the ropes in the third.
Brendan Harris hit a rare three-run single in the second for the Twins. The runners were in motion on Harris' fly ball to shallow left that glanced off Chris Duncan's glove for a hit that briefly put the Twins ahead 3-2.
Slowey lasted only three innings, matching his shortest outing of the season after entering 6-1 in his previous eight starts. He gave up five runs on six hits, remaining tied with Toronto's Roy Halladay for the victories lead while falling to 3-1 with a 4.43 ERA in interleague play. The Twins are 11-6 against the NL.
Most of Slowey's problem was Pujols.
"He's great for the game. A tremendous hitter, a tremendous athlete, everything I've heard he's a tremendous player," Slowey said. "It doesn't make it any easier giving up a couple of home runs to him."
Skip Schumaker added three hits and scored on both Pujols homers for the Cardinals, who totaled three runs during a three-game losing streak.
Six Cardinals relievers retired 16 of the last 17 hitters. Ryan Franklin worked the ninth for his 18th save in 19 chances, and first in a week.
Todd Wellemeyer lasted 2 1/3 innings, the shortest outing of his two years as a starter. He allowed three runs on four hits and four more walks, giving him eight in his last eight innings.
"I just feel like if I hadn't gone to the pen and tried to change something, the guys would think this game isn't worth working for," La Russa said. "He had it, lost it. He's searching."
Pujols is 8 for 16 with six RBIs against Minnesota after his first homers against the Twins. He has homered against every big league team but four -- the Orioles, White Sox, Athletics and Rangers.
After Pujols homered twice into the visitor's bullpen in left center, the Twins pitched to him carefully. Pujols drew his major league-leading 24th intentional walk with a runner on third and two outs in the fourth and walked on five pitches with a man on first and two outs in the sixth.
Twins reliever Bob Keppel allowed two hits in four scoreless innings in his debut for Minnesota, and first major league appearance since April 29, 2007 with the Rockies. Keppel, from suburban St. Charles, is a former sandwich draft pick of the Mets in 2000.
Wellemeyer is 1/3 with a 6.82 ERA in six starts this month and could be in danger of losing his spot in the rotation. He's 3-5 with a 5.70 ERA at home. ... Slowey is 7-2 with a 2.99 ERA in 11 career interleague starts. ... Twins C Joe Mauer grounded out as a pinch hitter in the ninth. ... Twins pitchers walked six batters a night after issuing none for the eighth time this season on Friday.