The Astros' No. 2 prospect allowed two hits over five shutout innings as Triple-A Oklahoma City beat Iowa, 6-3, on Wednesday.
Cosart, who did not figure into the decision, struck out three and walked one for the RedHawks. He faced two over the minimum and recorded eight of his 15 outs via the ground ball, which was all part of the plan.
"I wanted to establish fastball and that was really what got me through the game," he said. "My curveball wasn't there tonight, and for the most part, I was able to execute the fastball down in the zone and get some double plays. When my fastball is down, it's got some movement to go with the velocity."
Cosart earned his first Pacific Coast League victory in his last appearance, allowing an unearned run over two innings of relief. After yielding seven earned runs in his first two starts for Oklahoma City, the 22-year-old right-hander has allowed just three hits over his last seven innings.
"The first two starts, I started off the game really strong and I ran into one bad inning where I was leaving pitches in the zone," he said. "Hitters at this level, if you leave anything in the zone, they are going to hit mistakes really well."
Cosart's season has been a difficult one in part because of blisters. The Texas native estimates he's missed about six starts this season because of the problem, which landed him on the disabled list. Missing that much time renewed Cosart's focus for the stretch run.
"I just want to finish up strong, really attack the strike zone and limit the walks," Cosart said. "Some of my starts in Double-A, I had a few more walks than I wanted. Mainly being down in the zone and execute all three pitches. I know it's easier said than done. Keeping the blisters away the last three or four starts and get something positive going heading into next year."
Brian Sanches struck out three and gave up a hit over 1 2/3 innings of relief to earn his first win. Jose Valdez allowed a hit in the ninth en route to his 17th save.
Brad Snyder hit a two-run homer and scored twice while Matt Dominguez, Houston's No. 4 prospect, was 2-for-3 with a double and an RBI.