Saint Katherine, a NAIA school, trailed 33-23 at the break. The Firebirds stayed within striking distance but couldn't get closer than nine points in the final 10 minutes. Clark nailed a 3-pointer and Jared Brownridge made two free throws to pull ahead 69-55 with 3:24 remaining.
Clark was 3 of 4 from long range and 7 of 9 from the floor and became Santa Clara's 20th player to eclipse the 1,300-point mark.
The Broncos made 28 of 51 field goal attempts (54.9 percent) while limiting Saint Katherine to 23-of-56 shooting (41.1 percent).
Aragad Abramian made 4 of 7 treys to lead Saint Katherine with 16 points. Anthony Miller had 15 and Lesean Gallbreath added 14.