The Bulldogs were trailing 3-2 in the eighth when they struck for three runs off Hoosiers reliever Ryan Halstead.
Henderson's one-out single sent Brett Pirtle (3-for-5) home with the equalizer and Porter later added a two-out hit, chasing home Henderson and Wes Rea with the key tallies.
Chad Girodo notched the victory, tossing 5 2/3 innings of one-run relief, as the Bulldogs advanced to play the winner of Wednesday's elimination game between Indiana and Oregon State.
Sam Travis, Scott Donley and Casey Smith each knocked in a run for Indiana.
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