The victory sends OU to its third straight Super Regional where it'll be seeking a return trip to the College World Series after last year.
"I feel very proud of this group and their perseverance through the weekend," said OU head coach Patty Gasso. "It's not always easy working through rain delays and things like that because you come out and you warm up then you have to change your clothes, go eat lunch, come back, put your uniform back on, warm up again. And it's a little unnerving, but it's just the way it is.
OU certainly had no problem with it Sunday afternoon against the Beavers.
Like she has the whole season, catcher Jessica Shults provided some major pop in the middle of the Sooner lineup, blasting a first inning grand slam to put the visiting Sooners on top 4-0.
She connected again on a solo shot in the fifth for her 18th homer of the year.
"I mean, it helps when you have great hitters around you like Keilani and Lauren Chamberlain throughout our lineup," Shults said. "So, I mean, I just saw good pitches today. So, it was just it felt good."
Both right fielder Erica Sampson and left fielder Brianna Turang reached and then designated player Katie Norris ripped home Sampson on a grounder that just sped past the OSU shortstop.
That made it 6-0.
Meanwhile, pitcher Keilani Ricketts cruised for the third consecutive game, tossing a complete game shutout for the 13th time this season.
She struck out 10 and allowed just three base runners all game.
"Today I thought she was really on her mark," Gasso said. "I really love what she did. She was ahead of hitters, kept them guessing. You could see them uncertain of what's coming and kept them very off balance. I think Keilani pitches better with the lead, but I think she's tough when she's trying to keep us in the game as well."
Shults' five RBIs led the way, as she went 2-for-2, while Turang also finished a perfect 3-for-3 at the plate on the day.
OU will now face the winner of Sunday's Arizona-Notre Dame regional final game next week.
"I know that this team is starting to really hit their peak, which is exactly where you want to be right now," Gasso said. "And I know we are extremely anxious to be hosting Arizona here on our field."
The time for the best-of-three series is still to be determined.