STILLWATER, Okla. (AP) — Thomas Castellanos threw for 263 yards and four touchdowns, Malcolm Simmons returned the opening kickoff 97 yards for a score and No. 10 Texas Tech routed Oklahoma State 52-27 early Sunday to stay on track for a return to the Big 12 championship game and College Football Playoff.

The reigning conference champions, who lost to Oregon in last season's CFP quarterfinal, jumped out to a 21-0 lead and then withstood a 17-0 run by the Cowboys and their highly touted quarterback Drew Mestemaker to make it a game before halftime.

But any hopes of a late-night shootout between the Red Raiders (9-1, 6-1) and Cowboys (6-4, 4-3), coached by former Texas Tech player and coach Eric Morris, faded after that. Castellanos sat most of the fourth quarter after throwing a 30-yard scoring pass to Kenny Johnson to make it 42-20.

Texas Tech led 28-20 at the break and shut down Oklahoma State in the second half behind a defense that entered the weekend ranked 136th out of 138 FBS teams in passing yards allowed.

Mestemaker, who had passed for 300 yards in eight-straight games, threw for 277 yards — 186 in the first half — and two interceptions before giving way to freshman Broderick Vehrs with about eight minutes left in the game, which was played in cold and rainy conditions.

Vehrs led the Cowboys on a scoring drive in the final minute. With the loss, Oklahoma State saw its Big 12 hopes all but disappear.

Texas Tech: At Baylor on Saturday.

Oklahoma State: At Arizona State on Saturday.

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