The format was different, but Washington Twp. fell to Pioneer at a Class A regional for the second straight season.
At Tuesday's single-match regional, the host Panthers defeated the Senators 25-20, 25-15, 25-23.
During last season's four-team regional, Pioneer defeated Washington Twp. in a three-game semifinal (26-24, 25-22, 25-17).
Pioneer (29-7) meets Elkhart Christian (27-8) in semifinal action at the Caston Semistate on Saturday. Elkhart Christian defeated South Central 25-15, 25-18, 25-15 to advance.