Selected third overall in last month's Draft, the D-backs prospect allowed a hit and a walk over two scoreless innings as the Visalia Rawhide rolled to an 11-2 victory over the visiting Stockton Ports.
Bauer struck out three batters for the D-backs' Class A Advanced affiliate, only four days after signing his first contract.
"It feels pretty good. It was a lot of fun to be out there and it was a great crowd that came out to see me pitch," said Bauer, who is scheduled to face the Ports again on Thursday. "It seemed like a normal game once I was out there. But seeing all those fans put it into perspective."
Bauer went 13-2 with a 1.25 ERA and 203 strikeouts at UCLA en route to winning the Golden Spikes Award as the best college player. He was scheduled to pitch two innings or throw 40 pitches, whichever came first.
The California native struck out leadoff hitter Connor Crumbliss on a seventh-pitch changeup after falling behind 3-0 on three consecutive fastballs. He got Myrio Richard to chop a 1-2 pitch to shortstop Chris Owings for the second out, then threw two changeups to Michael Gilmartin before finishing him off with a curveball in the dirt.
In the second, Bauer retired Anthony Aliotti on a one-hopper to second base, but Petey Paramore stroked a 3-2 fastball to right field for the Ports' first hit. After striking out Jason Christian on a 2-2 curveball, Bauer walked Rashun Dixon but retired Mitch LeVier on a fly ball to center field.
"I was average, run of the mill," Bauer said. "I could have been better, but I learned a lot, and that is the most important thing. If you're looking at tonight on results, then I'd rate it pretty high. I was learning what works and what doesn't work. And on that basis, it was a success.
"I made some adjustments after my first pitches and then got in a rhythm. Sometimes it takes time to get comfortable on the mound."
Many of the 2,385 fans started filing into Recreation Ballpark long before the scheduled first pitch to watch Bauer, who began stretching some 90 minutes before game time. The 20-year-old started throwing from the center-field wall to the left-field line, gradually moving back until he was long-tossing from foul pole to foul pole.
That was not the only tradition Bauer brought with him from his collegiate days. When he came out for the first inning, he sprinted out of the dugout, walked up the back of the mound and crow-hopped his first warmup pitch to the plate -- as he did before every game at UCLA.
"I wouldn't call them rituals, but they're just things that help get me prepared and gets my body ready to pitch," he said. "I've been doing it for pretty much 10 or 11 years. Why change it when it's working?
"[The D-backs and I] have talked about it and they seem to be on board. They think the same way as me, and that is why I wanted to come here. They expect big things of me and I know I can meet their expectations. It's nice to have someone believe in me."
Earlier this week, Bauer signed a contract that guarantees him $4.5 million over four years. The right-hander can earn up to almost $7 million if he begins next season in Arizona and stays there through 2014.
"The negotiations were fine and they went really well. Both sides are happy with it," said Bauer, who took two weeks away from throwing after the college season ended before working out at the Texas Baseball Ranch. "I haven't made any big purchases yet. I'll splurge a little bit and go out for steak and sushi when that check comes in, and I'll help out the family and maybe buy a high-speed camera so I can look at my mechanics."
In college, Bauer threw 10 complete games, including nine straight to end the 2011 season. He left UCLA as the school's all-time leader with 34 wins, 460 strikeouts and 373 1/3 innings pitched and is the only Bruin to have at least 10 wins in two or more seasons. His career strikeout total ranks second on the Pac-10 list behind Tim Lincecum, who had 491 for Washington from 2004-06.
Michael Belifore (2-4) picked up the win in relief of Bauer, yielding three hits and two walks while striking out five over three scoreless innings. David Nick went 3-for-5 and missed the cycle by a triple, while Alfredo Marte added two doubles, a triple, two runs scored and an RBI.
Jacob Brown (3-5) took the loss after allowing seven runs -- four earned -- on six hits and a walk while fanning one over three innings.