Brown's final 3-pointer of the game came right before halftime and gave the Cowboys a 55-34 lead. He also hit both free throws he attempted.
Oklahoma State shot 56 percent from the field (32 of 57) and 60 percent from 3-point range.
Cowboys sophomore Michael Cobbins had his first career double-double with 13 points and 12 rebounds. Forte was flawless from the line, hitting all five free throw attempts.
By the time Brown had five 3s, Texas Tech had only four field goals.
Oklahoma State scored its most points in a Big 12 game this season, while the Red Raiders gave up the most points they have allowed all season.
Even as Brown was hitting from outside, the Cowboys also worked the ball inside, getting 26 points in the paint to Texas Tech's 18.
As they have all season, turnovers cost the Red Raiders, who committed 14.
The young Texas Tech team was just overmatched throughout the game and its shooting woes continued. The Red Raiders hit 20 of 54 from the field.