ETSU junior Grant Gallagher homered in the bottom of the 10th to break #1 Tennessee's 20-win start to the season, 7-6.
ETSU, now 16-4, scored in the first to go ahead 1-0, then Tennessee scored two unearned runs in the bottom of the inning. Tristan Curless homered to tie the game, then Cody Miller's 2-run shot put ETSU ahead, 4-2.
A Gavin Kilen home run and two doubles by Hunter Ensley had the Vols up 6-4.
Jamie Palmese, a sophomore, connected on a long ball in the ninth that tied the game at 6-6.
ETSU and UT both entered Tuesday's midweek clash in Knoxville ranked in the top four nationally in home runs.
At the start of the game, the Vols ranked second with 53 long balls this year while the Bucs were fourth with 45. Gallagher and Cooper Torres both rank in the top 15 nationally in homers for ETSU with 12 and nine, respectively.
Kilen has 10 on the year to lead UT.