San Diego State 63, North Dakota State 44: Xavier Thames had 30 points and five assists as the Aztecs knocked off the upstart Bison in NCAA tournament West regional play in Spokane, Wash.

Dwayne Polee II added 15 points and six rebounds off the bench as fourth-seeded San Diego State (31-4) advances to play Arizona or Gonzaga in Thursday’s Sweet 16 contest in Anaheim, Calif. Josh Davis grabbed 13 rebounds and the Aztecs held North Dakota State to one point over the final six-plus minutes.

Kory Brown scored 13 points for the 12th-seeded Bison (26-7). Leading scorer Taylor Braun had just seven points on 2-of-14 shooting and North Dakota State shot just 31.9 percent from the field.

The Bison trailed by eight with less than five minutes left before Thames scored back-to-back hoops to boost San Diego State’s lead to 55-43 with 3:21 to go. North Dakota State went more than five minutes without a point as the Aztecs added eight free throws to increase the margin to 20 with 40.9 seconds remaining.

Thames scored 14 first-half points and the Aztecs closed with a 15-3 burst to take a 30-23 halftime lead. San Diego State stretched the lead to 10 early in the second half before the Bison crept within five on a three-point play by Marshall Bjorklund with 15:37 remaining.

GAME NOTEBOOK: Thames’ scoring output is the most by a San Diego State player in NCAA tournament play. … Braun averaged just nine points on 5-of-25 shooting in North Dakota State’s two tournament games. … The Aztecs are part of the Sweet 16 for the second time in school history, also reaching the round in 2011 before losing to eventual national champion Connecticut.