The IronPigs gave up two runs in the ninth inning Sunday night in an 8-7 walk-off loss in Columbus.
Leading 7-6 heading into the ninth, Mauricio Robles walked in the tying run, then surrendered a game-winning sacrifice fly to Omir Santos.
Robles (0-1, 2.31), who suffered a loss and blown save, walked three in the inning.
The IronPigs held leads of 5-0 and 6-3 earlier in the game.
Carlos Zambrano, making his third start as an IronPig, pitched five innings.
Zambrano surrendered four earned runs on seven hits, striking out six and walking four.
Jermaine Mitchell had four hits and an RBI for the 'Pigs, while Darin Ruf added three hits and two RBIs.
Cody Overbeck had a two-run home run, and Steve Lerud added a solo shot.
Cody Asche and Josh Fields each had two hits. Asche drove in the game's first run in the first inning.
The IronPigs (40-36) will wrap up their series in Columbus on Monday at 12:05pm.