The Sooners (14-2, 4-0 Big 12) trailed 29-28 at halftime, but opened the second half on a 16-4 run, and Tech (12-4, 2-2) wasn't able to fully recover.
Texas Tech seniors Brown and Casey Morris led the Red Raiders with 11 points each.
OU senior forward Joanna McFarland was 5-of-8 shooting from the field, scoring 14 points to go with her 16 rebounds.
Oklahoma's starting five played most of the game. Senior Jasmine Hartman's 13 minutes — and one point — were the most of any of the Sooners' three bench players.
Ellenberg and junior guard Morgan Hook each played the game's entire 40 minutes.
“Some nights it's tougher than others,” Ellenberg said. “I think I did well at keeping myself composed and not letting myself get too tired at times. It was 40 minutes, but it didn't seem like it was that bad.”
Oklahoma returns to action Tuesday at Iowa State, then returns home for next Saturday's afternoon tilt with Texas.
“We've got a lot of room for growth; a lot of improvement to make,” Coale said of her team. “I love their spirit. I love the way they fight together, and their belief in one another and themselves.”