The loss dropped ACU (29-17) into Saturday's loser's bracket where they'll face either regional host Central Oklahoma or Lone Star Conference tournament champion Incarnate Word at 3:30 p.m. The Hornets (40-9) will play at 1 p.m.
The Wildcats received a quality start from Caitlyn Crain (13-7), who finished with four strikeouts in her 6.0 innings of work, but they struggled mightily at the plate in search of a clutch hit against Karley Schmelzer (19-3).
Schmelzer started the game with back-to-back walks, but caught a break when Keanna Winkfield was busted trying to steal third base. She then struckout Sara Vaughn for out No. 2 before getting Courtney Flanary to end the threat with a fly out.
The Wildcats would again leave two more stranded against Schmelzer in the second, and two in scoring position in the fifth to finish the game with seven left on base.
ACU didn't record its first hit against Schmelzer until there were two outs in the sixth when Kim Briggs slammed a double off the wall. The Wildcats then added a pinch-hit single from Kara Stutesman in the seventh.
Crain, meanwhile, held the Hornets scoreless until the fourth where a sacrifice fly by Amanda Self sailed deep enough to left to plate Stephanie Goodwin for the game's only run. ESU still had a chance to pad its lead further that inning, but first baseman Megan Brigance slid to catch a bunt along the first base line and then doubled off the runner at third.
Crain went on to punch out Jessica Brewer with a runner at second to end the fifth, and in the sixth, she struck out Katie Huffman with two runners aboard.
The Hornets managed just five hits, getting two from Goodwin.