The Orioles' No. 19 prospect fanned a career-high 11 batters and gave up two runs -- one earned -- on two hits over seven innings as Frederick bested Carolina, 8-2.
Berry retired 11 in a row at one point, a stretch that was broken up when Tyler Cannon singled with one out in the seventh inning. The 21-year-old left-hander threw 63 of his 89 pitches for strikes and did not walk a batter for the second straight start.
"The main thing was the fastball command," Berry said. "I got ahead of hitters and the offense picked it up and got us some runs. We cruised from there. I wasn't really focused on [the strikeout total] during the game, but I saw myself getting ahead of hitters and the put-away pitches were working. [Catcher] Joe [Oliveira] did a great job of calling the game, and we did a good job of setting them up as we planned."
Berry (4-4) struggled in his last two Carolina League starts, surrendering 11 runs -- six earned -- on 15 hits. The California native credited his mental approach on the mound as he surpassed his previous high of eight strikeouts, set most recently July 22.
"The difference was the focus level," Berry said. "I was more focused on the approach. I wasn't really focused on mechanical stuff, but trying to go in with a good mindset and compete."
Berry, who had Tommy John surgery in 2009, has split the season between Class A Delmarva and Frederick. He is 6-11 with a 4.50 ERA in 23 outings this season and is looking to end the season on a high note.
"Just keep at it every day," Berry said. "Working on different pitches and trying to hit spots. Just go out there and focus on the team and try to get W's out there."
Matthew Bischoff struck out two over two perfect innings of relief for Frederick.
Brenden Webb was 2-for-4 with three RBIs and three runs scored while Steven Bumbry doubled home a run for the Keys.