Santa Clara (5-0) remained unbeaten by hitting 51 percent of its shots and converting 17 of 21 free-throw attempts.
Raymond Cowels III scored 12 points for Santa Clara, hitting four 3-point shots.
Eastern Washington (1-5) had a 27-19 scoring advantage off the bench, but could not remain in contention.
Collin Chiverton scored 19 points, including 4-of-8 shooting from 3-point range.
Eastern Washington had a 39-29 rebounding advantage, getting a game-high eight from Justin Crogsile.
DouDou Gueye, a 6-foot-10 center from Senegal, has signed with Ball State as a graduate transfer from South Carolina State.
Duke freshman point guard Derryck Thornton Jr. is transferring to USC, his father announced on Friday to Scout.com.
We have changes at the top of the draft and a shakeup in the lottery, with teams starting to make their final decisions. Get the latest in Chad Ford's Mock Draft 9.0.