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.
Authorities say former Michigan State basketball player Keith Appling has been charged with carrying a concealed weapon and other crimes.
Point guard Jaylen Fisher, who reopened his recruitment after coaching changes at UNLV, has committed to TCU over a long list of schools.
Forward Kennedy Meeks, who has averaged 9.4 points and 6.5 rebounds at North Carolina, has pulled out of the NBA draft and will return to the Tar Heels.