The incident happened at the Addo Croc and Lion Ranch which borders on the Addo Elephant Park, 58km from Port Elizabeth.
Jan-Friederick Bredenhand, 30, from Worcester, was apparently sitting on the fence of the lion encampment at around 05:00 when a male lion attacked him, pulling him from the fence and ripping him to pieces in front of his friend, Simon.
Simon, whose surname is unknown, ran to get help and returned to the lion encampment with a couple from Grahamstown, Dominic and Veluchia Hassim, and Waldo Le Roux.
He flagged down Le Roux, who had coincidentally taken a wrong turn on his way to the Addo Mondi mountain bike race.
Le Roux told of how Simon "came out of nowhere and was suddenly in the road right in front of me. I drove past, but he looked so upset that I turned around. He was screaming: 'Please help me, my friend is being eaten by a lion.'"
"I tugged at the fence but I couldn't do anything," said Le Roux. "Even if the police were at the scene sooner they wouldn't have been able to do anything. He was already dead by the time we got there."
"Simon told us Bredenhand had wanted to show him how big the lions were when one of the males attacked him," said Le Roux.
Two other lions, another male and a female, also attacked Bredenhand. All three lions were put down on Sunday shortly after the attack.
The Hassims had been at the farm for a relaxing weekend and were staying in one of the chalets.
"I heard the screaming, but I thought it was people outside in the road. But then someone knocked on our door and screamed 'help, help, someone's being eaten by a lion!' so we went outside," said Mr Hassim.
Hassim was initially afraid that the lions might have escaped their encampment, which is not too far from the chalets.
"But then we ran to the encampment. It was horrific," said Ms Hassim.
"The one lion was gnawing on his ribs when we got there," she said.
This incident came as a second blow to Emmie Botha, one of the owners. Her husband, Lourens van Straaten, who managed the farm with her, was attacked by a male lion in July 2005 on the very same farm. He was declared brain-dead a few days later.
Van Straaten's son-in-law, Johnnay Janse van Rensburg, who currently manages the farm, said Bredenhand had only worked there for about a month.