LAS VEGAS (AP) Southern California kept stepping out of bounds, barreling into offensive fouls and throwing the ball into the hands of Washington State's players.

On an ugly offensive night, the Trojans clamped down defensively to avoid an early exit at the Pac-12 Tournament.

Boogie Ellis scored 17 points, Isaiah Mobley made two big defensive plays late and No. 21 USC overcame a rash of turnovers to hold off Washington 65-61 Thursday night in the Pac-12 quarterfinals.