With three weeks remaining in the regular season, the K-Mets trail Greeneville by four games in the Appalachian League West Division. Kingsport is 4½ games ahead of Johnson City for the second playoff spot.
Kingsport (28-20) got on the board first in the top of the second when Jeff Diehl doubled and was knocked home by Jeyckol De Leon.
Greeneville (32-16) scored runs in the third and sixth innings to take a 2-1 lead, but the Mets tied it in the seventh when De Leon drove home his second run of the night, a ground ball up the middle that plated Jonathan Leroux.
The Astros answered in the bottom of the frame when Alfredo Gonzalez homered to left center for the game-winning run.
Astros right-fielder Ariel Ovando ripped a two-run double an inning later to set the final score.
De Leon went 3-for-4 to lead the K-Mets, who outhit Greeneville 9-6 but could not get enough runners in scoring position.
Greeneville reliever Ryan Connolly (1-1) picked up the win after blowing the save in the seventh. Gonzalo Sanudo worked the final two innings to record his 11th save.
Kingsport starter Andrew Massie went 5 2-3 innings before being relieved by Edioglis Villasmil (1-1), who went the rest of the way and took the loss.
The rubber game of the series is Sunday night with first pitch set for 6 o’clock.