David Stockton hit a runner in the lane with 55.9 seconds left after Kelly Olynyk scored on consecutive possessions and No. 7 Gonzaga held off San Diego 65-63 on Saturday night for its fourth straight win.
The Toreros still had a chance after Olynyk missed the front end of a one-and-one with 8 seconds left, but Elias Harris blocked Ken Rancifer's shot and the Toreros couldn't get off another.
Harris scored 18 points for Gonzaga (21-2, 8-0 West Coast Conference), while Olynyk had 15 and Gary Bell Jr. 13.
The Bulldogs have won nine straight against the Toreros and 31 of 33.
Johnny Dee scored a game-high 21 points for USD (11-12, 4-4).