Stephen Holt added 13 points and Mitchell Young 12 for Saint Mary’s (26-5, 14-2 West Coast).
Marc Trasolini had 21 points and Kevin Foster 14 for the Broncos (21-10, 9-7).
Foster’s 3-pointer got Santa Clara within 63-62 with 4:08 remaining before the Gaels went on a 9-0 run—all on free throws—to take a double-digit lead with a minute to play. The Broncos missed five straight shots and had two turnovers during the stretch.
Dellavedova passed fellow Australian Daniel Kickert for the school record by making a spinning short jumper with 3:53 remaining in the first half. Kickert had 1,874 points from 2002-06; Dellavedova has 1,892.
Saint Mary’s came in having locked up the No. 2 seed and bye to the semifinals at the WCC tournament in Las Vegas.
With the loss, Santa Clara is the No. 4 seed, and BYU the No. 3 seed. Both schools receive a bye to the quarterfinals.