The Bison will play Lubbock Christian at 1 p.m. The Chaparrals upset Oklahoma City in pool play at OCU to advance.
OBU broke a scoreless tie in the fourth on an RBI single by Daniel Baptista.
The Bison climbed to a 5-0 lead with a four-run fifth inning on an RBI grounder by Mitch Prophet that plated two runs as an error. Dillon Usiak doubled in two more runs for the 5-0 bulge.
An RBI single by Cade McKewon put Rogers State on the board in the bottom of the sixth.
OBU answered with an RBI single by Prophet for a 6-1 edge.
The Hillcats made it 6-2 in the seventh on a Lance Rymel single, but Steven Messner worked through a bases-loaded jam to end the threat.
OBU tacked on an insurance run in the ninth on another Prophet RBI single.
Messner (8-4) went seven innings to get the win, striking out eight batters.
OBU had 10 hits, including two each by Prophet and Usiak.
The Bison are 45-12 in the season.