Ross DeRogatis led San Diego (13-9, 3-4) with 23 points and helped limit Gonzaga's Derek Raivio to seven points and 1-for-4 shooting from the floor. Nir Cohen scored 18 for the Toreros, who have lost nine consecutive games against Gonzaga.
The Bulldogs shot season bests of 67 percent from the field and 73 percent on 3-point field goals to extend the longest active home winning streak in NCAA Division I men's basketball to 49 games.
The Toreros trailed 42-34 at the half, wasting their 14-4 advantage in offensive rebounds in the half by shooting just 33 percent from the field in the first 20 minutes.
Gonzaga led only 56-52 before Micah Downs sank three 3-pointers in three minutes to help push the Bulldogs ahead 67-58 with 8 minutes left. Those were the only shots taken by Downs, a Kansas transfer, in his fifth game with Gonzaga since recovering from foot surgery.