DALLAS -- Baker Mayfield couldn't bring himself to reprise his flag-planting Columbus histrionics as the time ran out on Texas' comeback bid.

He wasn't thinking about the Sooners' rejuvenated playoff hopes behind an improved defensive performance, featuring two late defensive stops to salvage a 29-24 Oklahoma win. He wasn't thinking about obliging the Sooners fans chanting "Plant the flag! Plant the flag!" at the players celebrating on the Cotton Bowl field. (Senior center Erick Wren handled those responsibilities at the 50-yard line).

Mayfield was overwhelmed at the realization that washed over him as his teammates celebrated: His days in the Red River Rivalry were over.

"It started to settle in, that feeling that this was the last one," Mayfield said. "It's going to be hard for me."

It wasn't all gloom for the winning quarterback. After throwing for 302 yards and two touchdowns, Mayfield left the field with the Golden Hat Trophy on his head, literally galloping up the tunnel as Sooners fans cheered.

The Austin native grew up idolizing the Sooners in a land full of burnt orange and spent October Saturdays watching Bob Stoops and Mack Brown go head to head. The last three years, it's been Mayfield's turn to lead Oklahoma, and he made the most of his final appearance in the rivalry.

Mayfield found Mark Andrews wide open down the right sideline for a decisive 59-yard touchdown pass with 6:53 to play. That was after he left the game with an injury to his throwing shoulder. As both teams scuffled behind him, Mayfield struggled back to the Oklahoma sideline. His backup, Texas A&M transfer and Texas high school legend Kyler Murray, warmed up but never got to take a snap.

"Realizing it's the last one, you don't want to come out," Mayfield said. "You'll fight through a little extra pain for this one."

Texas lost the game but found a possible future Red River legend on its own sideline in Sam Ehlinger. A week ago, he helped beat Kansas State and amassed 487 yards of offense and two touchdowns. Saturday, he wrote the opening chapter of his Red River legacy with a standout performance, throwing for 278 yards and running for 106 more, scoring twice. He also channeled his inner Matt Leinart and helped shove 250-pound Chris Warren III into the end zone to get the Longhorns within 23-17 after trailing 20-0 in the first half.

Ehlinger left the game with 5:12 left after having his head slammed against the turf, but he told Texas' athletic trainers he was OK immediately. They ushered him into the medical tent on the sideline and, he said, quickly cleared him to return after putting him through "protocol."

"I wasn't ever confused where I was at all," Ehlinger said. "It was a hard hit. My head his the ground pretty hard, and they were just taking precaution."

The freshman quarterback spent a few snaps standing next to Texas coach Tom Herman after Shane Buechele was sacked, then returned with 2:24 to play. It was a move right out of the Baker Mayfield Playbook.

"Tough kid. You could tell by the way he carried himself," Mayfield said. "Just how the Austin boys do it, I guess. He's going to have a heck of a career."

Earlier in the week, Mayfield chided the Austin Westlake alum's career resume, which lacked a win over Mayfield's alma mater, fellow Austin high school blueblood Lake Travis. On Saturday, the quarterbacks looked a lot alike. And while Herman is still unwilling to publicly admit Ehlinger has swiped the starting job away from the older Buechele, there's no debate about who's stood out more through Texas' promising but frustrating 3-3 start.

"He showed me all he needed to show me in Los Angeles," Herman said of Ehlinger's 298 yards and two TDs in a road loss to USC on Sept. 16. "He's a tough dude. He doesn't get rattled. He's competitive as all get out. He didn't need to show me anything in his game. I've seen everything I need to see from Sam Ehlinger."

This was the first Red River Showdown since 1947 between two first-time head coaches, but it felt like a passing of the torch at quarterback. As one Austin legend said goodbye, another announced his arrival.

Mayfield is less likely to lower his shoulder and run you over as he is to dance around you a fling a ball downfield for a 30-yard gain. Ehlinger's more apt to take the former approach, but both are fun to watch and both can ignite a sideline. Ehlinger did it time and time again on Saturday on his 22 carries. He's now run the ball 61 times in his past three starts.

"He was great," Oklahoma defensive coordinator Mike Stoops said. "Love the kid. We look forward to the competition the next three years."

But Mayfield is the quarterback with two fourth-place Heisman finishes and an eye toward the trophy as a senior. He's the quarterback with a playoff appearance and an eye toward a second.

"He's an animal," Andrews said of his trash-talking quarterback. "He goes out on the field and he's a completely different person. I've never seen anything like it."

Mayfield got the win, but it's Ehlinger who still has time left to play in one of college football's greatest rivalries. As the adrenaline wore off and the lump in his throat started to form, Mayfield felt more than the satisfaction of victory.

He had to feel a little jealous, too.