Jio Fontan, who had a key three-pointer in overtime, iced the game by making one of two free throws with four seconds left for the margin of victory. Ari Stewart had made two free throws with 11 seconds left to give USC a 74-71 lead. Byron Wesley had two layups in overtime for the Trojans.
Fontan and reserve Aaron Fuller led USC (9-13, 4-5 in Pac-12 play) with 15 points apiece. Eric Wise finished with 12 points, 11 rebounds and five assists for the Trojans, who also got 10 points each from J.T. Terrell and Wesley.
UCLA (16-6, 6-3) was led by Shabazz Muhammad with 22 points and six rebounds while Travis Wear added 16 points and Jordan Adams finished with 13 points and three steals for the Bruins, who could have moved closer to the Pac-12 lead with a victory since unbeaten Oregon was trailing Stanford by 20 points in the second half Wednesday night.
The Trojans took control of the game with a 17-4 run to close the first half, sparked by 10 points from Fuller, for a 38-30 lead at halftime. Fuller's put-back basket with 6:30 left in the first half gave USC a 23-21 lead after eight unanswered points.
The Bruins built leads of 17-13 after Adams' jumper with 10:10 to play in the first half and David Wear's layup with 8:18 left before USC's run.
The Trojans opened a double-digit lead early in the second half on dunks by Dewayne Dedmon and Terrell, then had their biggest lead at 44-31 when Eric Wise hit a jumper with 15:41 left in regulation.
UCLA chipped away at USC's lead until Muhammad made a three-pointer with 4:01 left to cut the deficit to four and he made a layup with 2:56 to go to leave the margin at 63-61.
Fontan and Larry Drew II, who finished with eight points and eight assists, traded baskets to leave the Trojans ahead, 65-63, but Adams made a jumper with 31 seconds left to tie the score.
Wise was called for a charge on the ensuing possession and Drew missed a three-pointer at the buzzer, sending the game into overtime.
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