A beleaguered bullpen stepped up, too, preserving the one-run lead over the final 2 1/3 innings.
"That's huge," Miller said of the team's second one-run win this year. "Those are the really big games that you have to get. Those are good wins for us as a team."
It was a win earned by Miller and saved by the bullpen, which didn't buckle under late-inning pressure. Joe Kelly, who had been recently buried in the bullpen, closed the seventh with an assist from center fielder Jon Jay. Trevor Rosenthal threw a 98-mph fastball past Ian Desmond to strand a pair of runners in scoring position in the eighth. And Edward Mujica, who tiptoed around trouble last Thursday in Philadelphia to collect his first save of the season, earned his second without introducing any unnecessary intrigue.
"I'm just trying to be ready for whatever situation and pick up my teammates," Mujica said. "[Since] the first save, I am just preparing my mind for the ninth inning. That's where they are using me right now."
Miller positioned the bullpen for redemption by hardly deviating from his bread-and-butter fastball all evening. He let the aggressiveness of Washington's lineup play into his ability to elevate the fastball with success, and the deceiving late life on the pitch had the Nationals struggling to make solid contact with it.
The fastball was working so well for Miller, in fact, that he didn't throw a single changeup in his 98-pitch effort. The right-hander estimated that he mixed in only 10-15 curveballs.
"Obviously, they have a really good lineup over there, but I faced them in the spring and I know that they'll swing at the ball up," Miller said. "That's definitely one of my out pitches, going up in the zone. I guess you could say it's one of my weapons. … It's a tough lineup, so it was a good test for me."
"You can't go out there and try to teach someone deception," added manager Mike Matheny. "The ball just comes out of his hand a little different. They see it's pretty straight. It's not 105 miles per hour. But they have trouble catching up to it. That's deception and that's late life."
Miller struck out five Washington batters during his first turn through the batting order and didn't allow a hit until the fourth. It could have been argued, too, that the leadoff single should not have been ruled as such, as Allen Craig was seemingly in position to corral Pete Kozma's one-hop throw to first base. Craig was handcuffed, though, when the ball clipped the edge of the grass.
The inability to record an out on the play came back to sting St. Louis when, with two outs, Miller allowed consecutive run-scoring doubles to Ian Desmond and Anthony Rendon. That evened the game at 2, erasing the lead Craig provided with his own two-out double an inning earlier.
The Cardinals inched back in front in the sixth when, after Matt Holliday was hit in the arm leading off the inning, Carlos Beltran and Yadier Molina strung together singles, Molina's plating the go-ahead run off Nationals starter Dan Haren. The first four hitters of the inning reached base, setting the Cardinals up for a big frame that never did come to fruition.
The Cardinals' chances to keep tacking on were first sapped by Jay, who grounded into a base-loaded double play, 3-2-3. The inning then ended when Miller went down swinging with the bases again full.
The Cardinals were fortunate that the additional runs would not turn out to be needed. After serving up the fourth-inning doubles, Miller didn't allow another baserunner until the seventh.
"He's great," Craig said. "He just goes right after guys and throws strikes. He works fast. It's a lot of fun to watch."
When Miller got himself into trouble in the seventh, Kelly and Jay -- neither of whom has had much in the way of season highlights -- bailed the rookie starter out.
Kelly, in just his second appearance since April 7, entered with two out to face pinch-hitter Chad Tracy, who sent a soft liner to right-center. Jay kept the tying run from scoring by making a sliding basket catch.
"I'm just happy I was able to contribute," Jay said. "I got a pretty good jump on it. I said, 'Somehow this ball has to be caught.' I'm glad I was able to make the play."
Though the save would eventually go to Mujica, credit Rosenthal with maneuvering his way through the toughest part of Washington's order in the eighth. Two baserunners reached before Rosenthal struck out five-hole hitter Desmond to strand the potential tying run at third.
"That's the situation I want to be in… the game on the line," Desmond said. "He just got me out today."
A Cardinals bullpen that entered the night with a 5.51 ERA then welcomed an uneventful ninth. It marked the first 1-2-3 ninth the Cardinals have had in a save situation this season. Mujica is now 2-for-2 in save chances since stepping into the closer's role.
"It was perfect for what we needed today," Matheny said. "We needed he and Rosey both to come out and give us a chance to hold that small lead."