The Sounds shaved a 4-0 deficit to one after seven innings, but Round Rock busted the game open with a five-run eighth in posting a 9-4 decision.
Starter Nic Ungs (2-3) was charged with the loss, giving up four runs on seven hits in six innings.
Mitch Stetter tossed a scoreless seventh, but the visitors started the deciding surge against Luis Pena with three runs in just one-third of an inning and two more against Tim Dillard in two-thirds of an inning. However, four of the five runs were unearned. Joe Bateman finished with a scoreless ninth.
Second baseman Chris Woodward led the offense with two hits, including a solo homer and two RBIs.
The Stars' latest skid reached three games as they suffered a 7-4 defeat at Birmingham.
David Welch (11-3) suffered his second setback in his last four starts, allowing six runs on 10 hits in four innings, his shortest outing since June 30.
The Manatees (27-32) outhit Jupiter, 10-7, but they couldn't dent the scoreboard except a single tally in the fourth. The Hammerheads broke the tie with runs in the seventh and eighth for a 3-1 victory.
Joshua Butler started and gave up one unearned run in 3.1 innings. Rafael Lluberes worked 2.2 scoreless innings, but Jupiter registered the go-ahead run against Josh Wahpepah (2-5) and added an insurance run against E.J. Shanks.
Third baseman Kenny Holmberg, subbing for the injured Taylor Green, went 3 for 4 with a double, while right fielder Chuck Caufield and shortstop Brent Brewer finished 2 for 4. Both of Brewer's hits were doubles, while Caufield also had a two-bagger.
The Power (39-21) lost their third straight to Asheville, 12-8, as their lead in the South Atlantic League's Northern Division slipped back to one-half game over Lakewood.
West Virginia was too friendly to the Tourists, committing five errors as the visitors scored four unearned runs against starter and loser Evan Anundsen (11-7), who was tagged for nine runs on six hits and one walk in 3.1 innings. Jose Garcia didn't allow any runs in 2.2 frames, but Asheville reached Robert Wooten for three runs in the seventh to seal the outcome after the Power had clawed back to within 9-8 with five runs in the fifth and three in the sixth.
Second baseman and lead-off batter Eric Farris was the lone West Virginia player with more than one hit, going 2 for 5 with two runs. Right fielder Caleb Gindl went 1 for 4, but his only hit was a grand slam with nobody out in the fifth. It was Gindl's 12th long ball of the season and third in as many games and fourth in his last six outings.
The Brewers (7-16) took a much-needed night off. They begin a two-city, four-game road trip Friday at first-place Billings.
These Brewers also had the night off, one day after posting only their 10th victory of the summer and fourth in the second half, a 6-5 triumph in 10 innings against the Athletics.
The Brewers host the A's on Friday night as they play only eight more games.