San Francisco (9-11, 2-5 West Coast) won despite collecting just 17 rebounds.
The Dons made up for that discrepancy in other areas, hitting 16 of 17 free-throw attempts and building a 35-16 scoring advantage off the bench.
Dickerson hit three 3-point field goals and had three steals. Cody Doolin had seven assists.
Portland (8-13, 1-5) had a 37-33 lead at the half. It outscored USF 32-24 in the paint and had an 11-7 edge in second-chance points.
Maryland point guard Melo Trimble has withdrawn from the NBA draft and will return to College Park for his junior season, sources told ESPN.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.