Michael Kirkham, 30, was pronounced dead at 8:25 a.m. at Aiken Regional Medical Centers as the result of a brain hemorrhage, Aiken County Coroner Tim Carlton said.
Kirkham had competed in six amateur matches, but Saturday's Confrontation at the Convocation, held at the University of South Carolina Aiken's Convocation Center, was his first professional match, Carlton said.
The full-contact combat sport involves a variety of fighting techniques.
Kirkham, of Gaston, competed in one of 15 fights during the MMA event.
"During the event, he had received several blows to the head during the first round of his match," Carlton said.
"The referee stopped the match. He lost consciousness, and he never regained consciousness," he said.
The coroner and officials of the State Athletic Commission are reviewing video of the match to determine whether any charges will be filed.
An autopsy will be conducted today in Newberry.