Albuquerque (70-64) saw a 4-1 lead disappear in the seventh inning only to rally from 6-5 down with four runs in the eighth.
"There was nothing easy about this one," manager Lorenzo Bundy said.
Pinch hitter Brian Barden led off the eighth with an infield single. Former Isotope Brent Leach (0-2) retired the next two batters but Tony Gwynn Jr. reached on a single up the middle to keep the inning alive.
Reliever Dustin Molleken came in and walked Scott Van Slyke to load the bases. Chili Buss then lined a shot to right field that Sean Halton barely missed, landing instead for a two-run double.
"I was just looking for something out over the plate to hit," Buss said. "I got obviously a pretty good break that (Halton) wasn't able to catch that one cleanly. He had a little trouble seeing it but either way I'll take it."
Alex Castellanos cashed in two insurance runs with a bloop single to shallow left-center.
"Offensively we came through with the big inning," Bundy said. "A lot of two-out hits in that inning. But we also had other opportunities offensively, situation-wise, guys on third, we left guys on third three times. We could have made our life a little bit easier.
"I expect us to execute better, I really do."
Nashville (51-83) picked up a run in the ninth on former Isotope Eugenio Velez's one-out, RBI triple. Peter Moylan then struck out Sean Halton and got pinch hitter Hainley Statia to fly out to left field to earn his fourth save.
"I know one thing, they can swing the bats," Bundy said of the Sounds. "When they get the bats going they can hit some balls hard."
The Isotopes had built a comfortable early lead thanks to some blunders by the Sounds. Buss had a two-run sacrifice fly in the first inning as center fielder Kentrail Davis caught the ball but tumbled down the hill.
In the fourth inning, after catcher Robinzon Diaz's solo homer cut the lead in half, a throwing error by Diaz led to Angel Castro and Dee Gordon both scoring to make it 4-1.
Castro, who had singled for his first professional hit in 25 career at-bats, was also fairly solid on the mound. He finally ran out of steam in the seventh inning as the first two batters reached on a walk and an error.
Both runners would come around to score as pinch hitter Hunter Morris scorched reliever Sean White (5-6) with a two-run double down the right field line. Davis would then blast a three-run homer to put Nashville ahead 6-4.
Castro's final line saw him charged with three runs, two earned, on three hits and three walks while striking out four in six-plus innings.
"Castro pitched really good," Bundy said. "He did a very nice job. Unfortunately we couldn't hold the lead."
Albuquerque picked up a run in its half of the seventh as Tony Gwynn Jr. tripled and Van Slyke singled him home, though it could have been more as two runners were left stranded.
The players made up for it with their rally the following inning.
"It was a fun game," Buss said. "Everyone's playing super loose right now, regardless of the score. Everyone's happy to be home and get a couple wins under our belt."
The Isotopes will look to make it four in a row against the Sounds on Saturday at 7:05 p.m.