He did so, too, while minimizing distractions, both in the context of the game, as well as his season.
"We needed him tonight," manager Mike Matheny said. "No question about that. It shows a lot about the kind of pitcher he is. There have been a lot of distractions. But I think it's part of the maturing process to put those behind you and continue to throw and make good pitches like you can. It's a great job by him."
Zeroing in on Tuesday, in particular, Garcia wasn't rattled when several things behind him went wrong.
When Carlos Beltran lost a fly ball in the lights, Garcia followed with an inning-ending strikeout. A ball dropping in between three defenders in the seventh didn't faze the left-hander either. He got out of that jam by inducing a double play with runners on the corners and a two-run lead.
Garcia never let up, even as the Cardinals' offense missed chances to give the lefty more breathing room.
"It's definitely one of my best games of the year when you talk about command," said Garcia, who lowered his season ERA to 3.99. "I just feel like today was a game that something happened behind me and I was able to block that and keep worrying about the next hitter. Sometimes a bad thing happens when it gets away from you. But today I was able to get out of it."
In addition to ignoring potential in-game distractions, Garcia has done his best to unload himself of external ones, too.
Prior to his last two road starts, Garcia pitched so poorly on the road that the Cardinals altered their rotation so he could just pitch at home. That three-inning start in San Diego on Sept. 10 also prompted a closed-door meeting with Matheny.
"We had some good talks," Matheny said. "I encouraged him to keep pitching and to not let these distractions get in your way."
But for all that attention given to Garcia's glaring home/road splits, his last two starts away from Busch Stadium have been among his best this year.
He limited the Dodgers to one earned run in six innings in Los Angeles on Sept. 15. Garcia followed with a quality start at home before piecing together this gem, which came in a ballpark where Garcia was previously 0-3 with an 8.87 ERA in five starts.
"I'm not going to lie to you and say I didn't think about it, that every time I come here it hasn't been good," Garcia said. "But at the same time, when I go out now, all I'm worried about is making one pitch at a time and helping my team win."
"I had a good view out there, and he had some of his best stuff," Jon Jay said of Garcia. "His sinker was really working and he did a really good job today. He really set the tone today."
Garcia had to set the tone because the offense couldn't. The Cardinals swarmed the basepaths all evening but left several runs on the table early due to a lack of timely hitting.
Astros starter Lucas Harrell faced 26 batters during a five-inning start. Six of them reached with a walk; another seven tallied a hit.
"I was terrible," Harrell said. "I felt like the first two innings I was trying to get a feel for the game. It felt like I had never picked up a baseball before. It was embarrassing. It was bad."
Even still, Harrell left with his club only down, 2-0.
The Cardinals grabbed a first-inning lead when Jay singled and scored on Yadier Molina's sacrifice fly. With two outs in the second, Garcia doubled and scored on Jay's single to center. In those two innings, though, the Cardinals also stranded a combined five runners.
A double play then squashed a third-inning rally. St. Louis loaded the bases with no outs in the fifth and didn't score then, either. Beltran, with a 3-0 count, grounded into a double play. Pete Kozma ended the frame with a groundout.
"We got enough of what we were looking for," said Beltran, who is 0-for-8 in the series. "It happens."
The Cardinals finally were able to tack on a pair of insurance runs off Houston reliever Hector Ambriz in the eighth. Kozma doubled home Daniel Descalso on a one-out hit-and-run. Jay collected his second RBI of the game by then pushing Kozma home on a fielder's choice.
Allen Craig helped to preserve that four-run lead by making a diving stop to start a double play in the bottom half of the inning. With a four-run cushion, Matheny was able to give closer Jason Motte a second straight day of rest.
The Cardinals wrap up the road portion of their regular-season schedule on Wednesday against the Astros, whom they've now beaten 10 straight times.
"We've just gone out and played well," Matheny said. "We have to do the same thing tomorrow or else we'll get embarrassed. You can't take any team, anybody for granted for a second."