Allonzo Trier, who was playing his second game after missing two games under NCAA suspension, missed his first nine field goal attempts before making a steal and a layup for a 59-53 cushion with 3:12 left.
Parker Jackson-Cartwright had eight points and three assists for the Wildcats (24-7, 14-4 Pac-12), who survived 38.8 percent shooting to win their fifth conference title in the last eight seasons. They finished the game on a 13-1 run.
Freshman Justice Sueing had 17 points and five rebounds and Kingsley Okoroh had eight points and nine rebounds for the Bears (8-23, 2-16), who won only one league game in the calendar year, 74-70 over Oregon State on Feb. 3. They beat Stanford on Jan. 30.
The Wildcats, who already had clinched the No. 1 seed in the Pac-12 tournament, will meet the winner of the Arizona State-Colorado game in the quarterfinals Thursday.
Ayton has 21 double-doubles, one short of the school freshman record set by Al Fleming. He is two short of Kevin Love's Pac-12 freshman record.
Ayton had his double-double at halftime, with 14 points and 11 rebounds, as Arizona took an 11-point lead late in the first half in a game that tightened quickly.
Cal scored the final seven points of the half to trim an 11-point deficit to 38-35, and Sueing scored the first four points of the second half to extend the run for a 39-38 lead.
Ayton made two free throws with 5:28 remaining for a 55-53 lead that sparked the final run, although Arizona's lead was never greater than four until Trier's steal and layup.
Neither team shot well. Cal made 38.9 percent and was 3-of-16 from 3-point range. Arizona hit 5 of 18 3-pointers.
Trier entered the game as one of three Division I players shooting 50 percent from the field, 40 percent from 3-point range and 85 percent from the foul line. The others were Weber State's Jerrick Harding and Georgetown's Marcus Derrickson.
--Field Level Media
California | Arizona | |
Justice Sueing 17 | Scoring | DeAndre Ayton 26 |
Marcus Lee 2 | Assists | Allonzo Trier 7 |
Kingsley Okoroh 9 | Rebounds | DeAndre Ayton 20 |
Don Coleman 5 | Free Throws Made | DeAndre Ayton 7 |
Nick Hamilton 2 | Steals | Rawle Alkins 2 |
Kingsley Okoroh 2 | Blocks | Dusan Ristic 2 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
California | 54 | 38.9 | 3-16 | 9-15 | 7 | 27 | 4 | 6 | 12 |
Arizona | 66 | 38.8 | 5-18 | 23-26 | 13 | 37 | 4 | 5 | 12 |