ARLINGTON, Texas -- The Big 12 title game didn’t come back to haunt the league.

Baker Mayfield put the exclamation point on his Heisman campaign.

And Oklahoma all but clinched a spot in the College Football Playoff with a resounding 41-17 victory over TCU at AT&T Stadium.

Mayfield tossed touchdowns on two of his first three plays of the second half on his way to passing for 243 yards and four touchdowns overall. Mayfield also had a 54-yard dash out of the pocket, the longest run of his career.

Baker Mayfield took over in the third quarter for the Sooners and finished with four TD passes overall. Photo by David Stacy/Icon Sportswire

After TCU fumbled away the ball on its first snap of the game, which the Sooners returned for a touchdown, the Horned Frogs clawed their way back through the first half, thanks to a pair of Kenny Hill jump-ball touchdown throws to Jalen Reagor and John Diarse.

The Oklahoma defense, however, put the clamps on Hill in the second half and shut out the Horned Frogs.

And Mayfield began to take over.

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On his first play of the third quarter, Mayfield connected with Mykel Jones on a stop-and-slant for a 55-yard touchdown. Then on the second play of Oklahoma’s next drive, Mayfield found Marquise Brown over the top of TCU’s defense for a 52-yard touchdown bomb. The Sooners led by 21 and the rout was on.

The game-clinching scoring barrage was just the latest magnificent set of moments for Mayfield in a season loaded with them.

If there were somehow any doubts left about him winning the Heisman Trophy next weekend, Mayfield doused them with another spectacular performance against the Big 12’s top defense. He also moved ahead of former Oklahoma quarterback and Heisman winner Sam Bradford for the FBS record for passing efficiency rating in a career.

The Sooners will have to wait until Sunday to find out their opponent in the College Football Playoff. But there will be no doubt about their inclusion. Before capturing its 11th Big 12 title, Oklahoma was No. 3 in the CFP rankings this week.

After missing the playoff in two of the first three years, the Big 12 brought back the conference title game for the first time since 2010.

Leading up to Saturday, there were some nerves around the league -- and in Norman -- about the Big 12 potentially playing its way out of the playoff if Oklahoma lost.

Mayfield alleviated those concerns just seconds into the third quarter.