That represents a four-game swing in an eight-day span following the Cardinals' 19-inning loss to the Pirates on Aug. 19. Since then, the Cards have won six out of seven. Pittsburgh, on the other hand, has won just once.
"We're playing against really good teams and teams we have to beat," said starter Kyle Lohse, whose night prematurely ended because of a 34-minute rain delay. "We're down that home stretch, and we have to start doing the things we need to do to get in the postseason. We are seeing some life, seeing some good things coming together."
Sandwiched between these two clubs in the race for the second NL Wild Card spot are the Dodgers, who trail St. Louis by 2 1/2 games. The Cardinals will get their head-to-head chance against Los Angeles next month. Right now, though, the opportunity is there to bury the Bucs.
"We talk about this road trip, and it's exciting," said manager Mike Matheny, whose club is on a 10-game swing through Cincinnati, Pittsburgh and, later in the week, Washington. "It's an exciting time in the game, kind of watching everything unfold. And you're right in the middle of it."
This three-game series opened with a marquee matchup between team aces Lohse and A.J. Burnett, both of whom cruised early. Burnett was eyeing a Major League-high-tying 16th win. Lohse had a personal seven-game winning streak on the line.
Lohse breezed during his first run through the Pirates' lineup, retiring all nine in order with 36 pitches. The fourth inning, however, presented plenty of problems.
The 30-pitch frame opened with three straight singles, the last of which was an RBI knock off the bat of NL MVP-hopeful Andrew McCutchen. Josh Harrison's sacrifice fly later in the inning drove home another run.
Lohse, who last lost on June 15, hadn't had an inning that difficult all month. He entered the night having given up only three runs in his first four August starts.
"For whatever reason," Lohse said, "I kept falling behind guys and was getting predictable a little bit."
But the Pirates offered the lead right back in the fifth, and the Cardinals pounced.
Yadier Molina singled and scored on Skip Schumaker's double, which McCutchen rolled his ankle on while trying to retrieve the ball. That eliminated a potential play at the plate.
After a wild pitch moved Schumaker to third, he trotted home when Lohse chopped a hit off Burnett's outstretched hand and into center. Burnett wasn't so much frustrated with his inability to make the barehanded play as he was with his pitch selection.
"Maybe if I hadn't shaken off [catcher] Rod [Barajas] -- he wanted the hook, and I went with the heater and left the ball up a little," Burnett said. "I made a few mistakes -- that was one, another was the ball up to [Matt] Holliday."
That particular sixth-inning 3-1 fastball to Holliday was deposited as a souvenir in the seats atop the Clemente Wall. Holliday's opposite-field blast pushed St. Louis ahead, 3-2.
"If you can score back right away and take the momentum back, especially when you have one of your horses pitching, it gives him the confidence of going back out there with the lead again," said Holliday, who increased his NL-leading RBI total to 90.
The Cardinals padded the lead with a Molina sacrifice fly just before rain halted the game.
The storm rolled through fairly quickly, leaving Matheny with a decision that he viewed as nearly a toss-up: leave Lohse, who had a pitch count of 83, in to face the middle of the Pirates' lineup or lean on a bullpen that was without Edward Mujica to cover the final four innings?
Matheny chose the latter, weighing heavily on the fact that Lohse had the added fatigue of trying to score from first base on a fifth-inning double.
"Where we were was kind of no-man's land," Matheny said. "We could have gone either way. There wasn't a clear answer."
The decision to turn to reliever Lance Lynn made this Lohse's first start of fewer than six innings since May. Still, he left in position to earn the win, his team-leading 14th of the season.
"I was full-hearted ready to go back out there," Lohse said. "But knowing where I was pitch-count-wise, I didn't feel comfortable enough to go back out there just to get a quality start. I think that was probably the better decision to get the bullpen up and get them out there."
The 'pen, even though it wavered, managed to preserve that lead. Making his first appearance in relief this year, Lynn tossed a 1-2-3 sixth before allowing the Pirates to pull within one with an unearned seventh-inning run. Fernando Salas closed out that inning before Mitchell Boggs, Marc Rzepczynski and Jason Motte combined to wrap things up.
The margin of victory was also notable for St. Louis, which has not fared well in one-run games this year. Monday's victory improved the team's record in such games to 14-21. The Pirates are now 25-22 in one-run affairs.
"Having experienced players who've been through [a pennant race] before can help," Pirates manager Clint Hurdle said of the Cardinals. "They've got the weapons. That's a good ballclub. The starting pitching has been very productive, [and] their bullpen has settled down."