Just hours after USC fans broke out a "F*** the Mormons" chant during the Trojans' game against BYU -- the school issued an apology, saying it was all "distasteful" and "offensive."
It's unclear at what point during BYU's game against USC on Saturday night that the synchronized yelling happened ... video has yet to surface of it all.
But, multiple people reported hearing it loud and clear during the contest at the L.A. Memorial Coliseum ... forcing USC officials to apologize on Sunday.
"The offensive chant from our student section directed towards BYU during the football game last night does not align with our Trojan values," the school said in a statement.
"It was distasteful and we apologize to the BYU program."
What's interesting ... USC's quarterback, Jaxson Dart, is actually a member of the LDS Church.
The Cougars, though, were clearly unfazed by the disturbing chants from the Trojan-heavy crowd ... they ended up winning the game, 35-31, improving their record to 10-2.
The Trojans, meanwhile, dropped to just 4-7 on the year ... losing a chance to go to a bowl game later this season.