Shaqquan Aaron came off the bench to score 23 points, helping USC upset No. 8 UCLA 84-76 on Wednesday night in a Pac-12 game between cross-town rivals at the Galen Center in Los Angeles.

Elijah Stewart scored 15 points for the Trojans (18-4, 5-4 Pac-12), who won their fourth straight over the Bruins. De'Anthony Melton posted 13 points, nine rebounds, five assists and four steals. Chimezie Metu had 13 points and seven rebounds.

Isaac Hamilton scored 20 points to lead UCLA (19-3, 6-3). Lonzo Ball finished with 15 points and 10 rebounds. Aaron Holiday also scored 15 points while Thomas Welsh had 13 points and seven rebounds.

Welsh scored the first three baskets to help UCLA jump out to an 8-0 lead over the first three minutes. The Bruins went up 20-10 on a dunk by Ball, but the Trojans battled back to cut the deficit to one on a 3-pointer by Aaron.

Aaron made two more 3-pointers to key a 13-2 run that put USC up 36-28 with just over five minutes to play in the opening period. The Trojans stretched the lead to 10 on a 3-pointer by Jordan McLaughlin and carried a 50-38 lead into the break after Elijah Stewart made a 3-pointer with four seconds remaining in the half.

UCLA shot nearly 56 percent in the first half but committed 13 turnovers. USC shot nearly 46 percent and made nine 3-pointers.

The Trojans extended their lead to 15 on a 3-pointer by Stewart early in the second half. The Bruins staged 8-2 and 7-0 runs to get within four on a jumper by Hamilton, but McLaughlin and Melton made big 3-pointers in the final minutes to help USC fend off the charge.

NOTES: UCLA PG Lonzo Ball went into the game averaging 8.2 assists, the highest single-season average in school history. ... USC G Jordan McLaughlin was honored before the game for becoming the 37th player in school history to score 1,000 career points. ... USC F Bennie Boatwright missed his 15th consecutive game with a knee injury but could return next week.