USC fell to 55-49 in its all-time series with UCLA and was swept in the regular-season series by the Bruins for the first time since 2009.
The Trojans dropped to 9-5 in all-time five-set matches at UCLA and had its six-match winning streak in five-setters snapped (1995).
Junior OH Samantha Bricio finished with 21 kills and 11 digs for her 17th double-double this season (39th of her career).
Sophomore setter Alice Pizzasegola had 32 assists and a career-high 13 digs for her fifth double-double of the season; the sixth double-double of her career.
Sophomore libero Taylor Whittingham finished with 20 digs and had her 25th match of the season in double digits for digs. It was her 13th match with 20 digs or more this year.
Bricio moved into second place on USC's all-time career points list (1,706.0) ahead of Keao Burdine (1,689.5 points from 2001-04) and trails just Alex Jupiter (2,255.5 from 2008-11). Bricio also earned her 591st point this season, which moved her into sixth place in USC's single-season record books.
Junior MB Alicia Ogoms posted a career-high 12 kills and matched her career mark with 14.0 points.