Fort Wayne starting pitcher Max Fried (3-3) matched his career-high with eight strikeouts in five innings and allowed only one earned run, but ended up with the loss.
South Bend's Fidel Pena cranked out a leadoff home run to give the Silver Hawks all of the offense that they would need.
Brandon Sinnery (5-4) tossed the first nine-inning complete game of his minor league career to earn the victory.
Fort Wayne (3-11 second half, 46-37) managed just six hits, as it was shut out for the third time in a week.
Sinnery struck out eight without walking a batter. The TinCaps had only one runner reach scoring position in the game and never one past second base.
South Bend (10-5, 54-30) scored a second run off Fried in the top of the fifth courtesy of a Rudy Flores single, two errors, and a sacrifice fly by Pena.
The Silver Hawks added four insurance runs in the top of the ninth inning against TinCaps reliever Roman Madrid.
With the loss, Fort Wayne dropped to 1-11 against South Bend this season. The TinCaps have lost five in a row.
Up NextFirst pitch: South Bend at Fort Wayne, today at 7:05 p.m.
Probable starters: FW/Matthew Shepherd vs. SB/Jesse Darrah
TV: Xfinity Channel 81
Radio: ESPN 1380-AM