Kevin Pangos scored 26 points and Gary Bell Jr. added 17 for eighth-seeded Gonzaga, which beat Marcus Smart and the ninth-seeded Oklahoma State Cowboys 85-77 in the West region of the NCAA tournament on Friday.
The Bulldogs (29-6), in their 16th straight NCAA tournament, will play top-seeded Arizona on Sunday.
The refs called 61 fouls, and five players fouled out. Pangos made 12 of 14 free throws, most of them in the closing minutes.
Smart had 23 points, 13 rebounds, seven assists and six steals for Oklahoma State (21-13). He is projected to be a high NBA draft pick. He passed up the NBA draft last year. The Cowboys won five of seven games coming in, a run that coincided with Smart's returning from a three-game suspension for shoving a Texas Tech fan.