Buch held the Nationals to one hit over five innings -- a one-out single in the fifth by Sean Nicol broke up the no-hitter -- striking out six for his first win. He walked one before handing the ball off to the Winston-Salem bullpen; Chris Bassitt, Justin Collop, J.R. Ballinger and Taylor Thompson each threw a scoreless inning to preserve Buch's victory.
Ballinger allowed the game's only other hit when Zach Walters hit a leadoff single in the eighth but was stranded at third.
Potomac did have its share of baserunners, though, as Winston-Salem pitchers walked three and hit four, including three hit batters by Buch.
Buch, an eighth-round pick from 2009, had allowed at least four runs in each of his first three starts before shutting down the Nationals affiliate Wednesday.
Despite the Dash's season-high 14 runs on 13 hits, the game actually remained pretty close for the first five innings as Buch protected a 2-0 lead. Winston-Salem teed off with six runs in the sixth when Miguel Gonzalez hit a two-run single to chase Matthew Grace and Semien followed with a grand slam off Miguel Gonzalez, his first homer of the year.
Winston-Salem scored in the eighth inning for the first time all season when No. 3 White Sox prospect Trayce Thompson hit a solo homer to left, his third, and Gonzalez hit a bases-loaded double, giving him five RBIs on the day.