DALLAS — Baker Mayfield first donned the giant gold cowboy hat — awarded to the winner of the Red River rivalry — then ran around the field with the Oklahoma Sooners flag. The quarterback who grew up in the Austin area also made three long sprints down the field during the game. Those were to the end zone to celebrate touchdown passes to Dede Westbrook as the 20th-ranked Sooners held on to win 45-40 over the beleaguered Texas Longhorns on Saturday in the annual game Mayfield knows so much about. "It's special to me. Very special," Mayfield said. "I've been waiting a long time to actually come away with a win against these guys." Westbrook set a single-game Sooners record with 232 yards receiving on 10 catches, including three touchdowns longer than 40 yards . "He's got track-type speed," Mayfield said. After their 71-yard scoring hookup in the second quarter, the longest TD pass ever by the Sooners (3-2, 2-0 Big 12) against Texas, Mayfield sprinted along the Oklahoma sideline, then toward the middle of the field to acknowledge crimson-clad fans on the opposite side of the stadium before going to the end zone to meet up with Westbrook. They celebrated again after touchdowns of 47 and 42 yards in the third quarter. "You just look at the plays we gave up," Charlie Strong said, the embattled third-year Texas coach who has taken over calling the defensive plays. "You can't give up home runs thrown over your head." Mayfield lost to Texas as a freshman at Texas Tech in 2013 before transferring to Oklahoma, where he sat out a year before losing as the Sooners starter last October. This time, he completed 22 of 31 passes for 390 yards and overcame two interceptions in the first quarter, and a fumble in the final minute that his big right tackle Bobby Evans recovered. Samaje Perine added 214 yards and two touchdowns rushing on 35 carries as Oklahoma piled up 672 total yards in the highest-scoring game in the history of the rivalry. Texas (2-3, 0-2) led after two long touchdown passes by freshman quarterback Shane Buechele in the first 4 1/2 minutes after halftime. But Oklahoma went ahead for good when a Mayfield 4-yard touchdown run made it 28-27. While Oklahoma had four turnovers, Texas only turned those into three points. "Very fortunate to lose the turnover battle the way we did and still win," Sooners coach Bob Stoops said.