Victoria Sturm poured in a game-high tying 26 points and Lincoln held tough down the stretch as the Cougars beat Nitro, 63-55.
Allison Rockwell had 17 for Lincoln and Brynne Williams added 13.
It is Lincoln's first state tournament win since 2015. The Cougars advance to play No. 1 North Marion in Friday's semifinal at 1 p.m.
Baylee Goins had 26 to pace the Wildcats