What a tumultuous opening week in the Big 12, and our first set of in-season Power Rankings reflects as much. Texas skyrocketed up the rankings on the strength of its instant-classic, double-overtime win over Notre Dame on Sunday. But the shakeup from our August projections has as much to do with poor performances by Oklahoma and TCU as the Longhorns’ big win.

One week does not tell the story of a season. But the past three days have set a standard for 2016 that will be tough to match in terms of unexpected results. And while Texas sits atop the rankings this week, the unofficial big winner in the Big 12 from Week 1 was expansion candidate Houston, for its handling of No. 3 Oklahoma. The Cougars, however, remain ineligible -- for now -- to earn a spot atop the league’s Power Rankings.

1. Texas (1-0): The Longhorns won a 50-47 shootout in what is, so far, the game of the week nationally. No. 10 Notre Dame stormed back from a 17-point second-half deficit to force overtime on Shaun Crawford’s late two-point score of a blocked extra point. Freshman quarterback Shane Buechele threw for 280 yards and two scores in his Texas debut, and senior QB Tyrone Swoopes ran for three touchdowns, including the game-winner.

2. Oklahoma State (1-0): The Cowboys used a workmanlike effort to dispatch FCS-level Southeastern Louisiana 61-7. Thirteen receivers caught passes, including two touchdowns from Jhajuan Seales. Barry J. Sanders accounted for 76 all-purpose yards in his Oklahoma State debut, highlighted by a 57-yard punt return. No running back carried more than six times as the Cowboys jumped to a 28-0 lead in the opening 11 minutes.

3. Baylor (1-0): There's not much to learn here against an overmatched opponent, but the Bears led 48-0 at halftime en route to a 55-7 win over Northwestern State. Seth Russell threw for four touchdowns, and Shock Linwood rushed for 97 yards on nine carries as Baylor held the Demons to 78 total yards.

4. Oklahoma (0-1): The Sooners expected a test from Houston, but they got much more in their 33-23 loss. Oklahoma allowed the Cougars to score on each of their five first-half possessions, and then surrendered a length-of-the-field return of a missed field goal by Brandon Wilson early in the second half before Houston delivered the knockout punch. Oklahoma quarterback Baker Mayfield threw for 323 yards but could not overcome the miscues on defense and special teams.

5. TCU (1-0): The Horned Frogs overcame a 10-point deficit in the second quarter and led by just four points for a chunk of the fourth quarter against South Dakota State, an FCS team, before Kenny Hill threw for a score and ran for another to secure a 59-41 win. Hill enjoyed a nice TCU debut with 439 yards passing. KaVontae Turpin scored on an 81-yard punt return, and newcomer Taj Williams caught a touchdown. But it’s back to the drawing board for the TCU defense.

6. Texas Tech (1-0): Patrick Mahomes did his thing, throwing for 483 yards and four touchdowns as Tech rolled to a 69-17 win over Stephen F. Austin. The Red Raiders scored touchdowns on their first five possessions and spread the wealth to 17 receivers in accumulating 758 yards of offense, the second-highest figure nationally in Week 1.

7. West Virginia (1-0): There was not a lot of beauty here for the Mountaineers, though a 26-11 win over SEC foe Missouri looks pretty on paper. Junior college transfer Justin Crawford rushed for 101 yards, and Skyler Howard threw for 253, fighting through a rib injury. WVU lost left tackle Yodny Cajuste for the season to a knee injury.

8. Kansas State (0-1): The Wildcats couldn’t match the firepower of Stanford in their 26-13 loss, though defensively K-State looked solid. Jesse Ertz threw for 207 yards in his debut, an up-and-down night with one touchdown and one interception. He’ll need more help from the ground game, which managed just 92 yards.

9. Kansas (1-0): It’s a win -- the first for coach David Beaty and the first for the Jayhawks since Nov. 8, 2014. Montell Cozart and Ryan Willis combined to throw for 343 yards and five touchdowns in the Jayhawks' 55-6 rout of Rhode Island. This one was never in doubt as KU piled up 570 yards in a feel-good performance.

10. Iowa State (0-1): It was an ugly night in Ames as FCS foe Northern Iowa scored 16 points in the second quarter and got a 36-yard scoring drive with 2:49 left to beat Iowa State 25-20. Running back Mike Warren lost a fumble and quarterback Joel Lanning was intercepted to end Iowa State possessions after it fell behind late to seal a difficult debut for coach Matt Campbell.