The magic number for a second straight division title stands at nine.
"Tonight, we left it in our ace's hands," manager Mike Matheny said. "And he took care of business."
A day after the Cardinals suffered an extra-innings loss while wasting a strong Lance Lynn start, Wainwright dominated in what some teammates described afterward as the right-hander's best performance of the season. That's no small compliment, either, given that Wainwright has now thrown five complete games, three shutouts and 24 quality starts.
"Outstanding," was how his catcher, Yadier Molina, described it. "That's what we needed, and that's why he's one of the best pitchers in baseball. Everything was working for him. Everything."
Wainwright needed the offense to work for him, too, and it finally did late against Fiers, who was making his first appearance since hitting Marlins slugger Giancarlo Stanton in the face with a pitch. After being held scoreless since the first inning of Tuesday's 12-inning loss, the Cardinals found life in the seventh, one inning after Wainwright halted Fiers' no-hit bid by sneaking a single up the middle.
Fiers issued a one-out walk to Matt Holliday after the left fielder drove a pitch that had home run distance, but pulled just inches foul. The walk would do, however, as Matt Adams followed with a single that produced more than expected when outfielder Carlos Gomez slipped while trying to field the ball in center.
Holliday, sprinting first-to-third on the hit, was aggressively waved home by third-base coach Jose Oquendo. He scored just ahead of the tag.
"I just slipped," Gomez said. "Before I could even catch the ball, I was on the ground. ... Just one error right there, and it changed the game."
"We were having trouble getting a hit, let alone a run, so we have to pull out all stops and have to be overaggressive there," Cardinals manager Mike Matheny added. "When we're not getting things going, we have to make something happen"
Adams moved to second on the error, putting him in position to plate the insurance run when Jhonny Peralta followed with a single to center. It would send Fiers to his first career loss (five games, three starts) against the Cardinals.
"That definitely felt like playoff baseball out there with both guys going out there and having their 'A' stuff and both teams playing hard behind their pitchers," Adams said. "You could tell a run was going to be hard to come by. I'm just thankful we were on the right side of it."
Wainwright made do with the two runs of support en route to becoming the NL's second 19-game winner, joining Clayton Kershaw. He scattered seven hits, though none went for extra bases, and worked out of his only jam by inducing a bases-loaded flyout from Jean Segura in the third. The Brewers would not advance another runner into scoring position after that as Wainwright went on to finish nine innings on 102 pitches. He even dialed up to 95 mph on a pitch to Ryan Braun in the ninth.
This shutout came on fewer pitches than any of Wainwright's previous eight.
"It's good to be back making tough pitches when I need to," said Wainwright, who has followed his August lull by winning all four of his September starts. "This is a tough team over there, a tough lineup. They're fighting tooth and nail to stay in this race, so I knew we had a tough challenge. There was a good pitcher on the other side, too, so we needed some zeros up there."
The complete game was Wainwright's second in three starts, both coming against the Brewers, who have been on the wrong end of six Wainwright complete games over his career.
The win also sealed St. Louis' 21st shutout of the season, the most by any Cardinals team since the mound was lowered in 1969. Wainwright has started 11 of them.
"He's a special pitcher," Matheny said, "when he gets it all right."