The Purple Raiders (22-4) will play No. 4 seed Baldwin Wallace, a 68-65 winner over No. 6 seed John Carroll, in a semifinal game Friday at 8 pm at The Capital Center in Columbus.
Junior guard Tessa Pohovey (Strasburg/Tuscarawas Valley) finished with 11 points and sophomore Kori Weidt (North Olmsted/North Olmsted) also had 10 points.
Otterbein (11-15) was led by Katy Miller and Karli Volkmer who each had 13 points.
The Cardinals jumped out to a 23-5 lead in the game's opening nine minutes.
Despite being down by 18 points early on, the Raiders answered back with a 21-2 run of their own and took their first lead of the game at the 4:40 mark on a jumper in the paint by Weidt to put the score at 26-25.
A competitive Otterbein squad closed out the first half on an 8-2 run as Volkmer nailed a three pointer with two seconds left as the Cardinals took a 33-28 lead into halftime.
The Raiders would claw their way back in the second half and tie the game at 38 on a Pohovey layup at the 12:28 mark. The Cardinals answered back on a Kristi Kotterman jumper and take the lead 40-38.
Both teams would tie the score twice before freshman Brittany Kilgore (Northfield/Nordonia) scooped up a missed basket and made a layup to give the Raiders a 51-50 lead at the 3:40 mark.
A LaMattina steal with just under three minutes to play led to a fast break layup that put the score at 53-51.
Otterbein would once more tie score as Kotterman nailed a three pointer to put the score at 54-54 with 1:36 left to play.
Pohovey would sink a driving layup with 56 seconds left to give the Raiders their final lead as they went on to the 59-56 final.