Damion Easley, the stand-in starter at second base with Luis Castillo (quadriceps) on the 15-day disabled list, had two hits and an RBI for the Mets and finished 7-for-13 in the series.
The Mets had 39 hits and 25 runs the last three games of the series after losing the opener 7-1, and have double-digit hit totals four of the last five games.
Boggs (3-1) surrendered 11 runs, 10 hits, six walks and two wild pitches in six innings, taking a massive hit to his ERA with manager Tony La Russa intent on saving his bullpen for a three-game weekend series against Central-leading Chicago.
No relievers even warmed up while Boggs faced 10 batters in the third as the Mets went ahead 9-0, and La Russa was booed by the sellout crowd of 43,098 after making a brief visit to the mound, presumably to tell Boggs there would be no help.
The Cardinals used five relievers in an 8-7 victory on Wednesday and a sixth, Brad Thompson, worked four innings on Tuesday. Boggs, who entered with a 4.37 ERA and exited at 6.59, also committed a fielding error that allowed an unearned run to score in a three-run first.
Aaron Miles extended his hitting streak to a career-best 15 games, also the Cardinals' high this season. Yadier Molina and Adam Kennedy each had two hits in a game delayed for 26 minutes at the start by rain.
Pelfrey (6-6) allowed a run and six hits in seven innings, winning his fourth straight on the road, and the Mets have won six of his last seven starts. He had been 2-for-57 (.035) for his career before his RBI single in the third.
David Wright made the first and last outs in the third, which included an RBI double by Endy Chavez. Reyes leads the majors with 10 triples, two ahead of the field after a drive over the head of center fielder Rick Ankiel, and his 62 career triples tied Mookie Wilson's franchise record.
Delgado, who was 5-for-12 in the series with four RBIs, made it 11-0 in the sixth with his 15th homer.
