Kenton Akiemdien, 18, of Portland, Mitchells Plain was with friends at a party in Tafelsig on Saturday night.
His parents Ivan, 47, and Chantal Akiemdien, 38, say Kenton had been invited to the party of a girl he had met recently.
They say their son was an avid soccer player and had a two-year-old daughter.
He left school when his child was born and worked with his dad as a tiler and painter.
The mom says the tragedy happened on Kenton’s sister, Cammy’s 21st birthday.
Showing photographs of their son, the couple recall the chilling phone call they received to say that Kenton had been attacked.
Ivan says the killer apparently walked up to Kenton and stabbed him in the head while he sat with friends: “It was a new friend who was celebrating her birthday in Tafelsig.
“The adults were inside the house while the teenagers were outside in the yard,” the dad says.
“This person walked in and walked past Kenton and his friends. He turned around and walked towards Kenton and stabbed him in the head.
“The owner of the house called us and told us what had taken place.”
Kenton was rushed to the Mitchells Plain Day Hospital and then transferred to Groote Schuur Hospital.
“He was unconscious after he was stabbed,” explains Chantal.
“At 1.20pm they did a CT brain scan and he was declared brain dead. At 6.45pm, the machines were put off.”
The parents say they have no idea why Kenton was killed.
“We don’t know if he knew his killer, it was the first time he went to that girl’s house.”
Constable Carol Strauss confirms a case of murder is under investigation and that no arrests have been made.