The Lady Bucs (10-12) took the first game 4-3 but dropped the nightcap 4-1.
The Lady Bucs fell behind 3-1 in the opener before mistakes by Valpo helped tie the score at 3. Katy Jett then hit her second home run of the season to put ETSU up for good.
The Lady Bucs committed four errors and left 11 runners on base in the twin bill loss.
Jett led the Lady Bucs offensively in the opener, recording three RBIs to complement her homer, while Mary Catherine Vercoe (6-5) picked up the pitching win.
Darci Gilbert (3) earned the save in the first game, but took the loss in the second.
The Lady Bucs' home opener followed a trip to the Rebel Games in Kissimmee, Fla., where they won five out of six games.
Tennessee Tech 6, ETSU 4
JOHNSON CITY - A five-run Tennessee Tech fifth inning compounded by costly errors by ETSU doomed the Bucs in their loss to the Golden Eagles.
Tennessee Tech (10-6) trailed 3-1 entering the fifth but scratched out five runs on four hits and two ETSU errors.
The Bucs (12-7) took the early lead on single runs in each of the first three innings. Ryan Self scored on Anthony Russell's single in the first while Tanner Moore stroked a double in the second and came home on Justin Tramble's single.
C.J. Lee hit his first home run of the season for the Bucs in the third. Matt McGahey (0-1) took the loss.