USC center Omar Oraby, middle, had 12 points in a losing effort. (Danny Lee/Neon Tommy)

The loss was USC's sixth in seven contests. The Anteaters (6-7), who pushed UCLA into overtime earlier this season before falling by a point, picked up the program's first win against USC since 1983.

The Trojans last tied the game in the first half, 17-17, on an Aaron Fuller layup, before the Anteaters opened up a 20-8 run to take a double-digit lead into halftime and never looked back. Irvine shot 50 percent from the field before the intermission.

"For whatever reason, we ease into every first half," O'Neill said. "We won the second half, but that doesn't matter because we were down by 12 at the half at home."

USC forward Eric Wise chipped in 10 points and grabbed four rebounds against his former team.

"We weren't able to come back, that's the problem with digging yourself in a hole early," Wise said.

Center Omar Oraby led the Trojans' offense with 12 points, while Byron Wesley contributed with nine points and nine rebounds. The Trojans failed to break the 60-point mark for the third time in five outings.

Senior guard Jio Fontan handed out seven assists, but shot just 1-of-6 from the field to finish with two points.

The Trojans committed 16 turnovers, which led to an Irvine plus-11 advantage in points off giveaways. UCI guard Daman Starring connected on five of his six attempts from three-point range to lead the Anteaters with 23 points.

USC twice trimmed its deficit to five after going down by 10 with 5:35 remaining in regulation, but was held scoreless over the final three minutes. O'Neill characterized the team as a "rudderless ship in terms of effort and energy."

"The bottom line is, we have a responsibility as individuals to prepare for games and play as hard as we can, and until we do that, we're going to find ourselves on the short end of a lot of things," he said.

J.T. Terrell, USC's co-leading scorer coming into Thursday's game, did not see the floor until the second half. Terrell, who had logged just one minute in the Trojans' 70-26 drubbing of UC Riverside, knocked down two 3-pointers in 15 minutes of action in his second straight game coming off the bench.

"If J.T. plays defense like he did tonight, I'll play him. If he doesn't, I won't play him," O'Neill said.

USC next travels to Athens, Ga. to face the Georgia Bulldogs on Saturday at 10:30 a.m. PT. The Trojans won't return to Galen Center until Dec. 30 when they host the Dayton Flyers at 4 p.m.

Follow more of Neon Tommy's USC basketball coverage here.

Reach Staff Reporter Danny Lee here; follow him here.