Garcia threw seven innings of shutout ball, propelling St. Louis to a 5-0 win over the Brewers. He was coming off his worst start of the year, lasting just two innings in Kansas City, giving up five earned runs in an eventual 10-3 loss.
It was a rebound more often associated with Cardinals aces Adam Wainwright and Chris Carpenter than a rookie playing in his first full Major League season.
"I had a young man named Richard Dotson that won 22 games at about the same age," Cardinals manager Tony La Russa said. "He had a lot of composure.
"That's part of how you're going to succeed in this league. It's just not stuff. You've really got to keep your emotions intact because there are a lot of distractions, a lot of potentially up and down emotional moments. It's a special quality. You don't see it often when you see it."
Against the second-ranked offense in the National League, Garcia got stronger as the game wore on.
His biggest jam came in the third inning with the bases loaded, two outs and Brewers slugger Prince Fielder at the plate. Garcia coaxed a first-pitch ground ball, however, to escape the inning unscathed.
He had his way with hitters after that, retiring the next 12 and not allowing a ball to leave the infield. Garcia finished with seven strikeouts -- tying a season high -- and allowed three hits.
"That's a really tough lineup, a lot of tough outs, especially against left-handed pitching," La Russa said. "Against any kind of pitching. Early on, they had guys on base, and he kept his composure and made great pitches.
"He kept the ball out of the middle, and you just can't give him enough credit."
Garcia was not the only rookie to shine during the night.
Called up on Friday to give the Cardinals another bat on their bench, second baseman Tyler Greene found himself penciled into the starting lineup. He last played in the Majors on May 16.
He made his presence felt quickly, skying a home run to left field in the fifth inning to give the Cardinals a 4-0 lead. Greene belted a home run in his first game in April, as well.
"I was surprised," Greene said. "I haven't been able to do that in [batting practice], so it was a nice surprise for me. It carried well. To be honest, I was more shocked that I was able to keep it fair. I really got inside of that one and was surprised I was able to keep it down the line like that. I got into a hitter's count the second at-bat. I was looking for a fastball and was going to try to hit it hard when I got it."
The Cardinals opened the game up quickly in the first inning. Felipe Lopez singled to start. Albert Pujols bounced into his 14th double play of the season to score Lopez, and Nick Stavinoha plated Matt Holliday with a single.
The Redbirds tacked two more runs onto Brewers starter Chris Narveson in the third and fifth innings, and then scored an insurance run in the eighth on Holliday's double.
With Narveson being a former prospect in the Cardinals Minor League system, Greene was familiar with the left-hander's work.
"He has gotten better," Greene said. "He's got his pitches, and that's why he is being successful at this level now. He's really sharpened his pitches, especially his curveball."
Michael Bleach is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.