Aaron Gordon led the Wildcats (8-0) with 19 points and eight rebounds despite a wobbly 4-for-12 night at the free-throw line.
Brandon Ashley hit four 3-point shots for Arizona and finished with 18 points and 10 rebounds.
Kader Tapsoba scored 13 to lead Texas Tech (6-3). Jave Crockett scored 11 and Aaron Ross added 10.
Arizona took command early with a 10-0 run to start the game. The Wildcats finished with a 50-percent field goal percentage to 39.6 percent for Texas Tech. The Red Raiders were 1-for-11 from 3-point range and were out-rebounded 43-23.