Washington State 76, Southern California 51: Senior Brock Motum scored a season-high 31 points in his final regular-season home game and the Cougars cruised to their second straight win.Motum scored 21 points in the first half to help the Cougars (13-18, 4-14 Pac-12) take a 19-point lead at the break and finished with a game-high 10 rebounds. Royce Woolridge added 25 points, including five 3-pointers.J.T. Terrell scored 18 points to lead USC (14-17, 9-9), which opened the second half on a 22-9 run and cut the deficit to 48-42 with 12:05 remaining. The Trojans missed 20 of their 24 shots from 3-point range and were outrebounded 45-34.Washington State, which snapped a nine-game losing streak with a stunning 73-61 win over UCLA on Wednesday, squashed the Trojans' comeback hopes by using a 17-4 run to take a 23-point lead with 3:12 to play.The Cougars made 11 3-pointers and secured the No. 11 seed in the Pac-12 tournament and will meet No. 6 Washington Wednesday in Las Vegas. USC, which has lost four of its last six, is the seventh seed and will face No. 10 Utah in the first round.GAME NOTEBOOK: Washington State senior G Mike Ladd scored one point in his return to the lineup after missing the last six games with a knee injury. … USC G Byron Wesley, who scored a season-high 20 points in the Trojans' 72-68 win over the Cougars on Feb. 7, was held to five points on 2-of-8 shooting. …Washington State has won six of the last eight games against the Trojans.