DALLAS — Ryan Niblett returned a punt 75 yards for a decisive touchdown in the fourth quarter and Texas got a much-needed 23-6 win over sixth-ranked Oklahoma in the annual Red River Rivalry game on Saturday. Arch Manning completed 21 of 27 passes for 166 yards and the go-ahead 12-yard TD to DeAndre Moore Jr. on the opening drive of the second half for the Longhorns (4-2, 1-1 Southeastern Conference), who were coming off a loss at Florida that knocked the preseason No. 1 team out of the AP Top