J'Koby Williams broke a 64-yard touchdown run with under 3 minutes left, putting Texas Tech up 34-23 and effectively ending Arizona's upset bid in Lubbock.
Texas Tech erased a 17-10 halftime deficit by scoring 24 second-half points, taking the lead for good after Thomas Castellanos hit Kenny Johnson for a 27-yard touchdown late in the third quarter.
Arizona had chances to stay in front but missed an extra point after Kedrick Reescano's short touchdown run and later turned it over on downs in the red zone before a brief Texas Tech fumble gave it one more possession.
The win lets No. 13 Texas Tech rebound from last week's loss at Cincinnati and strengthens its position in a crowded Big 12 race against a No. 22 Arizona team that also entered 6-1.