Kelly Olynyk added 14 points and nine rebounds for Gonzaga (27-2, 14-0 West Coast Conference), which clinched at least a tie for the WCC regular-season title it yielded to Saint Mary's last year. It marks the 12th league title in 13 seasons for the Zags, who have set a team record for regular-season wins.
Chris Manresa scored 19 to lead San Diego (13-16, 6-8), which has lost four straight.
Gonzaga has never been ranked as high as No. 2 in the country. The Bulldogs have won 10 straight games since a last-second defeat at Butler. Their only other loss was to Illinois, and they have the best winning percentage in Division I.