The Portland Pilots fell to 4-6 in the West Coast Conference on Wednesday, losing 84-71 at San Francisco.
The Dons swept the season series, having won 87-81 at UP on Dec. 28.
Portland (12-10 overall) fell behind Wednesday by 18 points, cut the margin to 54-49 early in the second half but fell behind by double digits again with 2:05 left.
USF improved to 14-8 overall and 7-3 in the WCC, shooting 56 percent from the field.
The WCC leaders are No. 24 Gonzaga at 9-1 and Saint Mary's at 6-2.
Portland was 49 percent from the floor but trailed 17-7 in points off turnovers.
UP freshman guard Alec Wintering tied his season high of 18 points, and sophomore guard Bryce Pressley also had 15. Junior center Riley Barker got 10 points off the bench.
Portland returns to action at 7 p.m. Saturday at Santa Clara 10-13, 2-7).