Powell (3-1) went eight innings, giving up one run on four hits, striking out six and walking one on 91 pitches, 66 strikes.
The Rebels got their only run of the night in the first on a two-out homer by Darian Carpenter, his fourth long ball of the season. Waynesboro (18-13) responded with two runs in its half of the first, on an RBI singles by Travis Naraine and Eugene Vasquez.
Joe Marotta earned his first save of the season with a 1-2-3 ninth.
The Generals return to action on Monday on the road at Harrisonburg.
More online at www.WaynesboroGenerals.net.