Pacific (12-8, 6-2 Big West) also got 13 points from Travis Fulton, 12 points from Khalil Kelley, 11 points from Colin Beatty and 10 points from Sama Taku.
A basket by Kelley and four free throws by Taku in the final 2 minutes enabled Pacific to remain in front.
D.J. Seeley scored 23 points to lead Cal State-Fullerton (11-9, 4-4). Alex Harris scored 19 points and Kwame Vaughn contributed 13 points and nine rebounds. Cal State-Fullerton was 12 of 24 from 3-point range, and Pacific was 8 of 13.