The Reds (13-17), who took two of the series’ three games, spotted the Twins (17-13) a 2-0 fifth-inning lead when Charles Mack, with a runner on base, homered to right field.
In the bottom of the sixth, however, Bumpass clubbed a two-run homer of his own, depositing the ball over the right-center field wall.
Johnson’s sixth two-bagger of the season brought home Luke Berryhill, who had doubled his way aboard, in the eighth to put the Reds up 3-2. Second baseman Ruben Santana misplaying the throw back to the infield enabled Johnson to advance to third and eventually score on a Danny Lantigua groundout.
Max Smith opened the ninth by reaching second base (single, one-base error), but Elizabethton failed to make anything of it.
Greeneville won despite producing only five hits, with two of them coming from Johnson (2 doubles, 2 runs).
The Twins fared only slightly better, accumulating six hits. Mack and Smith tallied two apiece.
Patrick Raby (1-0) relieved starter Tyler Garbee to begin the sixth and put in three neat innings before Matt Gill worked the ninth for his first save.
Greeneville pitching piled up 14 strikeouts (no walks), including eight from Garbee. Raby added five.
Elizabethton starter Sawyer Gipson-Long blanked the Reds for three innings, then Cody Laweryson took over and made it through the seventh, yielding two runs. Erik Cha (3-1) threw the eighth.
The Twins rang up 11 Ks. Gipson-Long accounted for six and Laweryson four.
Next for Elizabethton is a trip to Bluefield while Greeneville visits Princeton. Both three-game sets start today at 6:30 p.m.