Washington State led nearly wire-to-wire thanks to 14-of-29 shooting from 3-point range and five scorers in double-figures, ending visiting Southern California's seven-game winning streak in an 81-71 decision Sunday in Pullman, Wash.

The Cougars (6-9, 1-3 Pac-12 Conference) went on an 8-0 run in the first half to take a lead they never relinquished, snapping a three-game skid on the season and scoring its first win over USC since February 2015.

Washington State also exorcised some lingering frustration in scoring its first conference win, answering every USC second-half comeback attempt after the Cougars coughed up a late nine-point lead in a 67-66 loss to UCLA on Friday.

In Sunday's contest, Washington State twice led by as many as 15 points after intermission. The Cougars outscored the Trojans 9-5 a little more than four minutes after the break thanks in part to five quick points from Justin Powell.

Powell scored 15 and shot 4 of 7 from 3-point range.

USC (11-4, 3-1) cut the deficit to six by the half's midway point, with a Reese-Dixon Waters and-one play culminating a 13-4 Trojans run.

But Washington State responded quickly, going on a 10-2 run over the next 2:50. The stretch included back-to-back TJ Bamba baskets, part of his 14-point scoring effort.

Mouhamed Gueye scored two of his 12 points on a put-back dunk and Powell capped the pivotal burst with a 3-pointer.

Powell was one of three Cougars to connect at least three times from beyond the arc. DJ Rodman and Jabe Mullins, who finished with matching game-highs of 16 points, shot 3 of 6 and 4 of 6 from deep, respectively.

USC, meanwhile, made just 3 of 18 from beyond the arc.

The Trojans' Drew Peterson matched the game's scoring high with 16 points, including 2 of 5 on 3-point attempts. Peterson also grabbed a game-high eight rebounds.

Kobe Johnson added 13 points and seven rebounds, Boogie Ellis went for 12 points and seven rebounds before fouling out and Joshua Morgan added 10 points.

--Field Level Media