Kopech, the Red Sox's No. 5 prospect, spun a career-high seven innings, giving up just one hit and two walks in his fifth scoreless start of the year.
"Getting through seven is big," Salem pitching coach Paul Abbott told MiLB.com. "I feel like the seventh inning is what the standard is for starters everywhere to get to, and when you're knocking on that door you start putting pressure on yourself to get there. Him getting through that and finishing it the way he did, feeling that fresh and looking that sharp, that will ease his mind going forward."
There is a reason Kopech is regarded as the No. 76 prospect in all of baseball, and he showed that as he pounded the zone, throwing 55 of his 89 pitches for strikes and finishing the masterpiece with 10 strikeouts.
Kopech has struck out 10 or more in three consecutive starts and in four of his past five trips to the mound. The right-hander has 85 strikeouts in 55 2/3 innings this season and a remarkable 32 strikeouts over his past 18 frames.
"He's a big, strong kid and there's no reason why he can't keep his velocity throughout the course of the game," Abbott added. "He's been a lot more efficient lately, throwing strikes. It's encouraging that he's been able to keep his velocity up, but it isn't surprising."
Through 10 starts with Salem, Kopech has a 1.23 ERA thanks to holding the opposition to one earned run or fewer eight times. In the other two starts, he gave up two runs.
The rest of the best performances from top prospects Wednesday:
• Lewis Brinson (Brewers' No. 2, No. 28 overall) pushed his average back up over .400 with Triple-A Colorado Springs after going 3-for-4 with two doubles and three RBIs. The 22-year-old is hitting .407 in 14 games with the Sky Sox since being acquired in a trade. Brinson drove in two with a double in the third and collected another RBI with a base hit in the fifth.
• Corey Ray (Brewers' No. 3, No. 32 overall) had another good day at the plate to put together his third three-hit game for Class A Advanced Brevard County. Ray, the Brewers' first-round selection, went 3-for-4 with a double, an RBI, a walk and a run scored.
• Blake Rutherford (Yankees' No. 6, No. 57 overall) continues to rake for Rookie-level Pulaski. New York's first-round pick is hitting .382 through 25 games with Pulaski after going 2-for-4 with a homer and two RBIs.
• Blue Jays' prospects Richard Urena (Jays' No. 1, No. 84 overall) and Dwight Smith Jr. (Jays' No. 27) each had a pair of hits and drove in a couple of runs as the duo combined to go 4-for-8 with four RBIs for Double-A New Hampshire. Urena extended his hitting streak to six games, but New Hampshire lost, 10-7, to Portland.
• Astros' No. 28 prospect Yordan Alvarez hit his first professional homer and went 2-for-2 with two RBIs for the Rookie-level DSL Astros. The game, Alvarez's 15th as a professional, also marked the first time the 19-year-old collected multiple RBIs.
• Joey Wentz (Braves' No. 8) picked up his first professional win and notched a career-high seven strikeouts for Rookie-level Danville. The 18-year-old lefty gave up four hits and walked three in five scoreless innings.
• After giving up 11 runs over his previous two starts, Brandon Woodruff (Brewers' No. 25) certainly turned things around for Double-A Biloxi. Woodruff was touched for just two hits over eight scoreless innings. The right-hander, who threw 76 of his 102 pitches for strikes, walked two and struck out seven.
• Cardinals' No. 23 prospect Bryce Denton had his second four-hit game of the season for Rookie-level Johnson City. Denton fell a triple shy of the cycle but went 4-for-4 with three RBIs.
• Mariners' No. 29 prospect Brandon Miller spun five perfect frames for Class A Short-Season Everett. The right-hander threw 40 of his 52 pitches for strikes, fanned five and lowered his ERA to 2.98 through 51 1/3 innings this season. Miller has now left without giving up an earned run in six of his 13 starts.
• Jeff Brigham (Marlins' No. 20) completed seven innings for the third time this season, giving up one earned run for Class A Advanced Jupiter. Brigham, 24, threw 56 of 75 pitches for strikes, walked one, gave up four hits and struck out four.
• Orioles' seventh-round pick Preston Palmeiro (No. 20) set career highs in hits, doubles, runs and RBIs in a breakout game for Class A Short-Season Aberdeen. Palmeiro went 4-for-5 with a pair of doubles, two runs scored and four RBIs.
• Pirates' No. 5 prospect Mitch Keller has now gone 23 innings without allowing an earned run for Class A West Virginia after putting up five zeros. After giving up three hits and striking out seven, the right-hander has a 2.46 ERA through 23 starts with West Virginia.
• Josh Ockimey (Red Sox No. 10) drove in a trio of runs and hit his 17th homer as part of a 2-for-4 night with Class A Greenville. It was the fifth time Ockimey has had three or more RBIs in a game and was the first baseman's first homer since Aug. 3.
• Chance Adams (Yankees' No. 10) is piling up the strikeouts for Double-A Trenton. The 22-year-old fanned 10 in 4 1/3 innings and has now notched 17 strikeouts over his past 8 1/3 innings. Adams gave up one run on three hits in the outing and threw 54 of his 87 pitches for strikes.
"Everything [was working], really," Adams told MiLB.com. "I was just focusing down in the zone. I had a game plan and attacked and was reviewing before the game. I stuck with my game plan, made a few minor adjustments and just tried to pound the zone."