The victory improved the 24-year-old's record and ERA to 5-3 and 4.37 for the I-Cubs, and he's struck out 63 hitters in 70 innings. Prior to being promoted to Triple-A, Zastryzny posted a 4.28 ERA and a 42-20 strikeout-to-walk ratio over 54 2/3 innings (nine starts) for Double-A Tennessee.
Iowa's bid for a combined perfect game came undone in the sixth inning when Omaha's Ramon Torres delivered one-out single to third base. The I-Cubs' staff ultimately yielded three hits while racking up 17 strikeouts in the game.
The rest of the best performances from top prospects Monday
• No. 36 overall prospect A.J. Reed notched his sixth multi-hit game since returning from the big leagues as Triple-A Fresno defeated Reno, 7-3. The Astros' No. 2 prospect connected on his 15th home run and his 22nd double as part of a 3-for-4 performance, and he also recorded three RBIs.
• No. 50 overall prospect Hunter Renfroe (Padres' No. 3) tallied three extra-base hits in his first three at-bats for Triple-A El Paso as part of a 3-for-5 night. The 24-year-old outfielder delivered his Pacific Coast League-leading 26th homer in the first inning and then followed with doubles in each of his next two trips of the plate, giving him 30 two-baggers for the season.
• No. 80 overall prospect Bobby Bradley (Indians' No. 3) belted his Carolina League-leading 20th home run to snap a 1-for-25 skid for Class A Advanced Lynchburg. After finishing 2-for-4, the 20-year-old first baseman owns a .251/.371/.480 slash line through 98 games.
• No. 89 overall prospect Richard Urena extended his hitting streak to six games with another multi-hit performance for Class A Advanced Dunedin. The Blue Jays' No. 1 prospect went 3-for-5 with three RBIs in and has collected 14 hits including two home runs during his streak.
• Braves No. 7 prospect Joey Wentz tossed four scoreless frames for Rookie-level Danville in a win against Pulaski. The 6-foot-5 left-hander, whom the Braves drafted in this year's Competitive Balance A round, scattered two hits, walked a pair and struck out four. Wentz has not allowed an earned run in five of seven starts to begin his career and Monday's performance lowered his ERA to 3.18. He's struck out 30 in 22 2/3 innings.
• Cardinals No. 20 prospect Dylan Carlson recorded a hit in his fifth straight game as he went 3-for-6 with two doubles, one triple and four RBIs for the Cardinals' Gulf Coast League affiliate. After getting off to a slow start, the 2016 first-rounder has raised his average from .179 on July 18 to .243.
• D-backs No. 6 prospect Taylor Clarke tossed five scoreless innings of four-hit ball to pace Double-A Mobile in a seven-inning shutout of Chattanooga in game one of a doubleheader. The 2015 third-rounder did not issue a walk and fanned nine -- one shy of his season high -- while throwing 62 of 83 pitches for strikes.
• Giants No. 14 prospect Clayton Blackburn hurled seven scoreless innings as Triple-A Sacramento blanked Salt Lake, 7-0. The 23-year-old righty allowed three hits, walked one and struck out five, with 65 of his 105 pitches going for strikes.
• D.J. Peterson drove in half of Triple-A Tacoma's eight runs in a win over Albuquerque. The Mariners' No. 8 prospect connected on a three-run homer -- his 17th of the season and sixth since joining Tacoma -- in the first inning against No. 44 overall prospect Jeff Hoffman and later added an RBI double en route to finishing 2-for-4.
• After failing to go deep in his first 48 games as a professional, Twins No. 25 prospect Trey Cabbage erupted to hit a pair of homers to help lead Rookie-level Elizabethton past Princeton, 6-1. He also tallied four RBIs in the contest, matching his career high.
"It was like getting a monkey off my back," Cabbage told MiLB.com of his first homer. "It really, really helped lift a weight off of me. I wasn't thinking that I needed to hit one out, but I wanted to have quality at-bats, square some up and have a good approach. I've hit some balls hard, but when that one finally went over the wall, it was kind of a relief and helped me feel comfortable."