The bleeding woman, who was found walking along Hammonds Ferry Road about 5 a.m. Saturday, told police she'd been hit by a car near the water treatment plant.
During the altercation, the woman -- who did not have an address -- said she ended up on the hood of a 1997 Chrysler sedan driven by Robert Michael Johnson, 29, a police report said.
With her holding onto the windshield wipers, Johnson slammed on brakes and threw the victim to the pavement, causing her to lose consciousness, the report said.
She and Johnson knew each other, according to the report.
Johnson was released from Aiken County Detention Center Saturday on a $5,000 bond, authorities said.