NORMAN, Okla. -- With the Big 12 title on the line, Oklahoma lost one Heisman contender to an injury.

Fortunately for the Sooners, they had another.

Behind quarterback Baker Mayfield, Oklahoma overcame the loss of wide receiver Dede Westbrook to coast past Oklahoma State 38-20 on a rainy Saturday to capture its 10th Big 12 championship and clinch a berth in the Allstate Sugar Bowl.

By toppling the Cowboys, the Sooners became the first Big 12 team in seven years to run the table in conference play.

Sooners quarterback Baker Mayfield (6) celebrates with wide receiver Jarvis Baxter (1) after throwing a touchdown pass. Kevin Jairaj/USA TODAY Sports

Midway through the second quarter, their chances of doing so didn't look promising. After rolling up 111 receiving yards, including a dazzling, 69-yard touchdown reception, Westbrook took a shot across the middle of the field from Oklahoma State safety Jordan Sterns. After lying on the ground for several seconds with an apparent head injury, Westbrook was helped to the sideline, where he remained the rest of the way.

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With Westbrook out, the Cowboys scored back-to-back touchdowns to grab a 17-10 lead. It looked as if the Pokes were primed to pull away. Instead, despite not having his favorite target and perhaps the best receiver in college football, Mayfield took over.

He led the Sooners on three consecutive touchdown drives, covering 76, 82 and 80 yards, including one to end the first half and another to begin the second. On the three possessions, Mayfield completed seven of nine passes for 101 yards and a pair of touchdowns. Between the first and third touchdown, Oklahoma State ran a total of four plays. By that point, the Sooners were firmly in control for good.

Leading up to the game, Oklahoma launched its Heisman campaigns for Mayfield and Westbrook, putting campaign-styled yard signs around campus and handing out buttons at the game. On Saturday, they both gave their closing statements.

Westbrook first. And Mayfield second.