"One of the things that went wrong, we did not convert and the other is they really got going offensively," said coach Ken Bone. "They did a nice job of picking up the momentum and the tempo of the game favored them.
"They made a couple tough shots during that stretch that really hurt us."
USC (11-19, 2-15) wasn't exactly lights out from outside, though, as the Trojans shot just 6 of 19 from the from beyond the arc, four of which in the second half. The Cougars didn't help themselves on the offensive end, either, shooting just 29 percent from the field in the latter half of the contest, including 10 of 35 from the 3-point range.
DaVonté Lacy led the way with 20 points on 5-of-19 shooting from the field and grabbed 10 rebounds.
Bone said he felt fatigue played a role in the second half, which came as a surprise considering his team had multiple days off following its loss to Washington.
Points in transition fueled the Trojans' attack midway through the game and they tallied 16 points off Cougar miscues.
Dexter Kernich-Drew said the Trojans' full-court press proved to be troublesome, particularly in the second half.
"We got lazy toward the end of the first half and through some pretty questionable passes in the second half," he said. "We didn't take care of the ball or have the focus that we needed to when that happens."
Early in the game, Woolridge showed flashes of the offensive game that has been absent all season. He knocked down a pair 3-pointers which he said were a result of shooting with confidence, and benefitting from a fast-paced style of play.
Woolridge scored nine of his 12 points in the opening period, but along with the rest of the team his game sputtered in the second half.
"The turnovers and other stuff, it just gets you out of the flow of the game," he said. "Turnovers, which led to their transition buckets, hurt us. I don't think it was necessarily them being better than us – they are a great basketball team – but we really hurt ourselves."
Bone said the game was "no doubt" his team's best chance to get a win and build momentum heading into the Pac-12 Tournament.
Washington State's regular-season finale is slated for 8 p.m. on Saturday against UCLA (23-7, 12-5).
Shelton finished the night with 11 points and 11 boards to notch his 11th double-double of the season.