The right-hander struck out nine batters over seven innings, allowing just three singles in the Sounds' 4-0 shutout of the visiting Tucson Padres on Wednesday.
Peralta (2-0) threw 61 of his 91 pitches for strikes and he retired 11 batters in a row at one point after surrendering hits in each of the first two frames.
Right fielder Caleb Gindl's fielding error allowed Kyle Phillips to reach base to lead off the sixth inning to snap the streak of consecutive outs. Drew Macias followed with a one-out single to left field to give the Padres their only runner in scoring position all night, but Peralta retired Pedro Feliz and struck out Matt Clark to keep the shutout bid intact.
A native of the Dominican Republic, the Brewers' No. 1 prospect worked a perfect seventh before turning a 4-0 lead over to Daniel Ray Herrera, who tossed two perfect innings to seal Nashville's fourth shutout of the year. It was the first time the Sounds blanked the opposition since a 19-0 rout of the Colorado Springs Sky Sox on Aug. 4.
Signed as a non-drafted free agent in 2005, the 22-year-old is having the best season of his six-year career. He was 9-7 with a 3.46 ERA and 117 strikeouts over 119 2/3 innings in 21 Southern League starts with Huntsville before his Aug. 11 callup, and he is a perfect 2-0 in his brief stint in the Pacific Coast League. His 117 strikeouts ranked third on the Double-A circuit at the time of his promotion.
In his Triple-A debut Friday, Peralta allowed three runs on six hits and a walk while striking out eight over six innings in a 13-3 victory over the Las Vegas 51s.
Last year, he was a combined 8-6 with a 3.79 ERA in 27 games -- including 25 starts -- between Class A Advanced Brevard County and Huntsville.