Saint Mary's 17-game win streak against USF came to an end Thursday night when a sluggish offensive effort resulted in a 73-62 loss at War Memorial Gymnasium.
Brad Waldow had 15 points and 13 rebounds, but the other Gaels starters struggled in the team's first loss to the Dons since 2006.
Saint Mary's (19-9, 9-6 WCC), which fell to fourth in the WCC, made just 5 of 26 attempts from 3-point range (19 percent).
USF (17-10, 10-5) used an 18-2 run in the first half to surge ahead by double digits early.
"We have to compete better," Saint Mary's coach Randy Bennett said. "For this time of year we're making way too many mistakes. I haven't done a good job of coaching this team."
Mark Tollefsen had 16 points, six rebounds and four assists to lead the Dons. Matt Glover and Kruize Pinkins also scored 16 points for USF.
North Carolina 74, Duke 66: Marcus Paige scored all 13 of his points in the second half, including two big baskets in the final 2½ minutes, to help the Tar Heels (19-7, 9-4 ACC) beat the No. 5 Blue Devils (21-6, 10-4) for their eighth straight win.
Leslie McDonald had 21 points for North Carolina, which rallied from 11 points down in the second half to snap a two-game home losing streak to Duke.
Jabari Parker and Quinn Cook both scored 17 points to lead Duke, which led 51-40 with about 15 minutes left before going cold from the field. The Blue Devils missed 13 straight shots and went scoreless for 6 minutes at one point.
"We looked tired or we didn't have life," Duke coach Mike Krzyzewski said. "And no matter what we did in a timeout, we just didn't have that spark."
A winter storm forced the game's postponement last week.
Santa Clara 70, Pacific 50: Brandon Clark had 17 points to reach double figures for the 18th straight game, and the Broncos (12-16, 5-10 WCC) used a stifling defense in beating the Tigers (14-12, 5-10) at Leavey Center.
Santa Clara held UOP to a season-low point total and allowed the Tigers to shoot just 32 percent from the field.
Ahead 39-29 with 13:02 to play, the Broncos used an 11-0 run over the next three minutes to take control with a 50-29 lead.
BYU 73, Gonzaga 65: Anson Winder scored 17 points and Matt Carlino added 15 to lead the host Cougars (19-10, 11-5 WCC) over the No. 25 Bulldogs (23-5, 13-2). Eric Mika added 13 points and eight rebounds for BYU, which snapped a five-game losing streak to first-place Gonzaga. Sam Dower scored 14 points for the Bulldogs, who shot 40.7 percent (22 of 54) from the field and couldn't overcome 16 turnovers.
Michigan St. 94, Purdue 79: Gary Harris had 25 points, Adreian Payne added 23 and the No. 13 Spartans (22-5, 11-3 Big Ten) hit a school-record 17 3-pointers in a road win over the Boilermakers (15-11, 5-8). Harris and Payne combined to make 10 3-pointers. Payne also scored eight points to open the second half to give Michigan State a 57-43 lead.
Connecticut 68, Temple 55: Shabazz Napier had 17 points, 11 rebounds and seven assists as the No. 21 Huskies (21-5, 9-4 American Athletic) beat the host Owls (7-18, 2-11).
Memphis 64, Rutgers 59: Michael Dixon Jr. scored 15 points as the No. 22 Tigers (20-6, 9-4 American Athletic) led from start against the host Scarlet Knights (10-17, 4-10). The victory extended Memphis' school record of 20-win seasons to 14 straight.
Oregon St. 68, Washington St. 57: Angus Brandt had 16 points as the Beavers (14-11, 6-7 Pac-12) improved to 11-2 at Gill Coliseum with a win over the Cougars (9-17, 2-12).
Saint Mary's 83, USF 64: Jackie Nared had 23 points and nine rebounds, and the host Gaels (20-6, 10-5 WCC) turned a two-point halftime lead into a 19-point win over the Dons (9-17, 4-11). Zhane Dikes led USF with 17 points.
Pacific 64, Santa Clara 47: The visiting Broncos (8-18, 4-11 WCC) shot just 38 percent from the field in a loss to the Tigers (15-10, 10-5). Nici Gilday led Santa Clara with 15 points.
Notre Dame 86, Wake Forest 61: Jewell Loyd had 29 points, and the No. 2 Irish (26-0, 13-0 ACC) beat the host Demon Deacons (14-12, 5-8).
The Associated Press and wire services contributed to this report.