Samora Mangesi tweeted photos of the injuries he sustained in the alleged assault, which he said happened on Friday.
He and his two female friends were called "monkeys", he said.
When they asked why they were being insulted, he was beaten unconscious.
During the alleged attack in the city of Johannesburg, Mangesi, who is a presenter for SABC, said he received injuries to his face and was bruised along the side of his body after being kicked on the ground.
"Even whilst I was being put in the ambulance, one of these guys tried to run my friend over with his bakkie [pick-up truck] and the paramedics had to intervene."
In the days following the attack, his memory was "very sporadic", he said.
"As much as they say I was awake, I don't remember being in the ambulance, arriving at the hospital nor much of the treatment."
He thought about "letting it go and just continuing with my life", but has now reported the incident to police, he added.
A police spokesman told the BBC that a case of alleged assault was being investigated.
News of the alleged assault has sparked anger on local social media.