Peralta (6-9) struck out a career-high 11, scattering two runs on five hits and two walks over six innings in Triple-A Nashville's 7-3 win over Memphis.
The right-hander's 11 punchouts bested his season high of eight from a May 1 win over Omaha. Those two are his only starts this year in which he's struck out more than six, after he fanned at least seven in all five of his outings with the Sounds at the end of last season.
Thursday's effort represented the highlight to what's been a turnaround month for the Dominican Republic native. He ended June with a 5.94 ERA and since has managed to lower it just over one full run to 4.92. His 100 strikeouts in 106 innings are seventh-best in the Pacific Coast League.
In five July outings, Peralta went 3-1 with a 2.20 ERA and 33 strikeouts while walking eight in 28 2/3 innings. It was his first month averaging at least a strikeout per inning after he struck out 157 in 150 2/3 innings between Nashville and Double-A Huntsville in 2011.
This year proved difficult in the early going for Milwaukee's top prospect. He allowed five or more runs in four straight starts from May 17-June 1 and then allowed four in just two-thirds of an inning June 22 against Oklahoma City.
But since then, he's thrown 34 1/3 frames across six starts for a 2.10 ERA with 37 strikeouts and 11 walks. That seemed more like the prospect who went 11-7 with a 3.17 ERA across 26 starts and two levels last year -- including a 2.03 ERA with 40 strikeouts in 31 innings after his callup to the Sounds.
Overall, Peralta has managed to bring his ERA down from a high of 6.83, where it stood June 1 after he went 1-4 with an 8.78 ERA in May.
In his first 13 starts this year, the 23-year-old was 1-8. In his next eight outings, he went 5-1. He also threw one inning of relief in the Majors for the Brewers earlier this year.
On Thursday, third baseman Andy Gonzalez powered Nashville offensively, going 2-for-5 with a double and three RBIs. No. 15 Milwaukee prospect Caleb Gindl added a double, two walks and two runs scored.