In game 1, a 2-run 5th was all the Sand Gnats needed to beat the Catfish, 2-1.
Juan Lagares' two-run homer spoiled a complete game by Wade Townsend and lifted Savannah to a 2-1 victory over visiting Columbus in the first game of Friday's twinbill.
Lagares' one-out blast to left field in the fifth inning was only the third hit given up by Townsend (3-2), who had faced the minimum through 4 1/3 frames.
A former first-round draft pick who missed all of last season while recovering from Tommy John surgery, Townsend allowed four hits over six frames and fanned nine without walking a batter. The complete game was the first of his professional career.
The second game was again decided in a single inning. Savannah scored 4 in the 3rd, en route to a 4-1 win over the Catfish.
Josh Thole's two-run single highlighted a four-run third inning as Savannah beat Columbus, 4-1, to sweep Friday's doubleheader at Grayson Stadium.
Thole lashed a single to left field, scoring Hector Pellot and Joe Holden. Thole came around to score on D. J. Wabick's base hit to give the Sand Gnats (12-29) a 4-1. Holden went 2-for-3 with a stolen base.
Savannah's Greg Mullens (3-1) won for the second time in his last three starts, allowing one run on six hits while walking two and fanning three in five innings. Emary Frederick struck out two of the last three batters of the game for his second save.
The series concludes tonight with the Catfish needed a win to salvage a split of the series. They have not lost a series this season.