Cedric and his now ex-roommate -- a guy named Clavens Charles -- got into an argument last weekend in Texas over their living arrangements, when all of the sudden Benson allegedly rocked Charles in the face.

According to the police report, Benson allegedly continued to strike Charles "with several more closed fists all over Clavens face resulting in severe injury to his face."

Cedric's attorney released a statement, claiming the NFL star was provoked in the attack -- and Charles was exploiting the incident as an opportunity to extort the running back.

Charles' attorney shot back with his own statement, calling the alleged attack "an unprovoked, violent assault" ... DENYING the extortion claims -- insisting Charles hasn't made a single request for money since the incident.

According to his attorney, Charles has already incurred THOUSANDS of dollars in medical bills ... and still has further medical procedures pending.