Appalachian (32-10) trailed 3-2 going into the seventh but knotted the game at 3-3 on Hector Crespo's solo home run to lead off the frame. However, East Tennessee State (20-24) answered with a leadoff walk and four-straight singles in the bottom of the stanza to retake a 6-3 advantage.
The teams swapped single runs in the eighth and the Mountaineers couldn't make it any closer in the ninth. The loss snapped Appalachian's seven-game winning streak but extended its skid versus ETSU to three-straight defeats.
Trey Holmes went 4-for-4 with a triple, RBI and run scored to lead the Apps' 12-hit attack. Preston Troutman also had a triple among his three hits and true freshman Brandon Burris went 2-for-5 with two doubles to raise his batting average to .403.
Although Appalachian banged out 12 hits, it left nine runners on base and had another thrown out at the plate to end an inning. Of the nine ASU runners left on base, four were stranded at third base.
Ryne Frankoff, one of seven pitchers used by the Mountaineers, issued the leadoff walk in the seventh to suffer his first loss of the season.
Clinton Freeman and Dylan Pratt had three hits apiece to pace ETSU.
First-place and 28th-ranked Appalachian returns to action on Friday when it begins a three-game Southern Conference series versus UNC Greensboro. First pitch is set for 6 p.m. at ASU's Beaver Field at Jim and Bettie Smith Stadium.