Tyler Haws scored 24 points, Anson Winder added 22 and the Cougars defeated the Pilots in Provo, Utah on Monday.
Kyle Collinsworth finished with 21 points and eight boards for BYU (11-4, 1-1).
BYU, which rebounded from a loss to Gonzaga in the WCC opener, shot 50.8 percent from the field.
Alec Wintering led Portland (10-4, 1-1) with 30 points.
Saint Mary’s 69, San Francisco 56: Brad Waldow scored 21 points on 10-for-15 shooting and hauled in 10 rebounds to lead the Gaels to a win over the Dons in Moraga, California.
The Gaels (9-3, 2-0), who shot 51.9 percent from the floor, opened the second half with a 9-2 run that included a 3-pointer from Desmond Simmons that made it 38-26 with 17:41 to go. The margin never fell below double figures the rest of the way.
Tim Derksen led the Dons with 16 points and Matt Glover had 10.
Pepperdine 69, Loyola Marymount 56: Jett Raines scored 17 points as the Waves opened WCC play with a win over the Lions in Los Angeles.
Amadi Udenyi made 3 of 4 from long range for 11 points as Pepperdine (8-4) was 8 of 14 on 3s. LMU (4-9) missed all six 3-point attempts, hitting 21 of 52 field goals.
Santa Clara 57, Pacific 40: Matt Hubbard scored 15 points, Jared Brownridge added 14 and the Broncos defeated the Tigers in Stockton, California.
Hubbard was 5 of 6 from the field, knocking down all three of his 3-pointers, to lead the Broncos (6-7, 1-1)
Alec Kobre was the lone scorer in double figures for Pacific (8-6, 0-2) with 11 points.
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