MLB.com's No. 6 prospect scattered five hits over six shutout innings in the Reno Aces' 2-1 win over the Iowa Cubs. He struck out five batters and issued two walks in lowering his ERA to 2.59.
Despite fighting groin injuries for stretches of the 2012 season at both Double-A Mobile -- where he began the year -- and Reno, Bauer (11-1) made his big league debut in late June.
The injury resurfaced just three innings into his first start with Arizona, and the organization sent him back to Triple-A to work on his command after posting a 6.06 ERA in four games in the Majors.
After a perfect first inning Monday, Bauer surrendered consecutive singles to Greg Rohan and Blake Lalli to start the second. But Lalli got doubled off first base on Dave Sappelt's flyout to right field and Bauer was able to escape unharmed.
Avoiding big hits with runners in scoring position became the theme of 21-year-old's night. The UCLA product stranded Tony Campana in scoring position in the third frame, and he tiptoed around a two-out walk to Lalli followed by Sappelt's base hit to left field in the fourth.
Bauer then stranded Campana at second base once more in the fifth, and he left Lalli -- representing the potential tying run -- in scoring position an inning later before turning a 1-0 lead over to the bullpen.
Arizona's top prospect threw 53 of 80 pitches for strikes, but he did not factor in the decision after the Aces lost the lead in the eighth and regained it in the ninth.
Zach Kroenke (6-3) earned the win in relief of Bauer. He gave up one run on three hits over two innings.
Iowa's Frankie De La Cruz yielded a run on five hits over five innings. He recorded four strikeouts and walked three batters. Jairo Asencio (0-1) gave up a solo homer to Adam Eaton which proved to be the decisive score in the game.