The Brewers prospect gave up an infield single over five innings in his first professional start and combined with Dan Britt on a one-hitter in the Timber Rattlers' 5-0 blanking of the Kane County Cougars.
The victory gave the Brewers' Class A affiliate a split of its doubleheader after it was beaten, 1-0, in the first game.
"We needed somebody to burn some innings and I jumped all over it. I was pretty excited about it," Garman said. "I got to hang out there a little bit longer than normal. Usually, my outings are just one or two innings, so I was jazzed.
"It doesn't matter if you're in the game at the beginning, the middle or the end, you still have to throw the ball over the plate. But as a starter, you get more chances."
Selected in the 17th round of last year's Draft, Garman (3-2) used an inning-ending double play to erase Geulin Beltre's one-out walk in the opening frame, then worked around Jacob Kuebler's single in the second. Only his own hesitation stopped him from making a play on Kuebler's tapper back up the middle.
"I wish I had been able to make that play," the 23-year-old left-hander said. "He didn't hit it very well, but I thought it was coming harder than it was. As a pitcher, it's just self-preservation. I didn't set my feet or get in front of it like I should have and I just stabbed at it. It was a pretty soft roller and it bounced off the end of my glove.
"If you can get guys to roll over pitches and get ground balls, it's OK. I wouldn't want to re-do that at-bat because I was pleased with the outcome. It if isn't tattooed and you get a weak ground ball, you're happy."
The University of Cincinnati product cruised thereafter, setting down the Cougars in order over the next three frames before turning things over to the bullpen.
"I'm pretty happy with it. To be part of a one-hitter as a professional is something that I'm proud of," said Garman, who lowered his ERA to 3.23. "I wasn't sure what to expect, but I'm glad it went the way it did.
"I was throwing my off-speed stuff for strikes and my catcher, Joey [Paciorek], was on the same page. I shook him off a couple times, but for the most part we were in a groove. I was able to get ahead a lot with first-pitch fastballs and then go to the off-speed pitches later in the count."
Britt retired all six batters he faced to finish off the Timber Rattlers' sixth shutout.
While Garman, who has made 33 relief appearances this season, enjoyed his start, he said he'll likely be returning to the bullpen.
"I was a starter for three years in college, but I was streaky," he said. "If they need me again, I'll jump right back out there, but if I had to guess I would say my starting days are over."
Mike Brownstein went 2-for-3 with a double and two RBIs and Chad Stang, Jason Rogers and Nick Ramirez plated the other runs for Wisconsin.
Kane County starter Santiago Garrido (1-4) took the loss after surrendering two runs on five hits and two walks while striking out a pair over four innings.