New York has lost 10 of 12 following a 9-2 stretch, falling to 70-70. The Mets, on the verge of taking the wild-card lead on Aug. 31 before Pedro Martinez faltered against Philadelphia, have lost eight of nine since then and dropped 5½ games back of Houston, which leads in the wild-card chase.
"We've got to see if we can get something going from the little funk we're in," Mets manager Willie Randolph said. "Obviously we've picked a bad time to go into a little swoon, and it's hurting us."
St. Louis cut the magic number for clinching its second straight NL Central title to 10, beating the Mets for the ninth straight time at Busch Stadium.
Carpenter (21-4) allowed three hits in seven innings, struck out seven and walked one, lowering his ERA to 2.21, second in the major leagues' to Roger Clemens' 1.57. He's 13-0 in his last 16 starts with a 1.36 ERA over that span.
"What a performance we're watching," Cardinals manager Tony La Russa said. "It's just been a privilege to watch this kind of excellence."
Carpenter said everything was working against the Mets.
"I made quality pitches over and over again and kept the ball down in the strike zone and kept them off balance," he said.
Carpenter has started 22 games in a row in which he allowed three runs or fewer while pitching six innings, the longest stretch of consecutive quality starts in the NL since Bob Gibson also did it 22 straight times in 1968.
"I faced Chris when he was in Toronto," the Mets' Doug Mientkiewicz said after going 0-for-3 and failing to get the ball out of the infield. "I thought he was the best I'd ever seen then. He's better now."
Carpenter gave up two hits in the first, then retired 16 in a row -- with just two batters hitting balls that reached the outfield -- before Carlos Beltran singled leading off the seventh. Three relievers followed him and completed a four-hitter, the 13th shutout for St. Louis this season.
"They might have the Cy Young," Randolph said. "They might have the MVP over there, too."
That was a reference to Pujols, who hit three homers in a span of five at-bats and has four in four games. He just missed another in the first inning, flying out to the warning track.
Pujols is hitting .338 with 39 homers and 106 RBI.
"He's been doing it over and over again," La Russa said. "Getting rallies started and driving in big runs. He's had a great, great year. Nobody's had a greater one."
Kris Benson (9-7) dropped to 0-3 in four starts since beating Pittsburgh on Aug. 16. He allowed four runs - three earned - and seven hits in 6 2-3 innings.
Benson matched Carpenter through five innings before Pujols hit a 415-foot homer to center leading off the sixth, just the fourth run for the Cardinals in 24 innings. So Taguchi's two-out RBI single later in the inning made it 2-0.
Pujols hit a 421-foot homer over the left-field bullpen in a three-run seventh for the second multihomer game of the season and the 12th of his career. Edmonds reached on an error by second baseman Kaz Matsui and rookie John Gall hit his first major league homer, a drive off Tim Hamulack that came in Gall's 21st career at-bat.
Jose Reyes singled to open the game and was erased trying to steal by Yadier Molina, who has thrown out 14 of 25 runners trying to swipe. Matsui singled, and Cliff Floyd walked with two outs before David Wright struck out.
- New York was blanked for the 11th time.
- Thursday marked the seventh anniversary of Mark McGwire's record-breaking 62nd home run, hit at St. Louis against the Chicago Cubs' Steve Trachsel.
- The Mets have not scored more than four runs in a loss since a 7-6 defeat to the Los Angeles Dodgers on Aug. 12.