Mathew Tomson, the only son of surfing legend Shaun Tomson, lost his life in "a tragic schoolboy prank" that went wrong, his father told hundreds of mourners on Tuesday.
And the heartbroken Tomson, whose eulogy was read by family friend, Norman Kinnear, told parents to teach their children that "they are not invincible".
Mathew, 15, a pupil at Clifton College in Durban, was found hanging by his school tie at his home at Virginia, Durban North, last Monday.
He was found by his mother Carla, who had made being Mathew's mother her "number one priority", her husband recalled.
In a telephone call to his father in Santa Barbara, America, Mathew told how much he loved his parents and how much he was looking forward to playing in the first rugby match the next day.
"An hour after the phone call, he was taken from us, from a prank gone awry. Our boy loved life and life loved him back," said Tomson.
The surfing star and "his remarkable wife" would miss their only son "more than the depth of the ocean and the breadth of the sky", he said.
"Hold your children tight and hold them tighter again. Love them with everything you have, every minute of every second of every day. Listen to them and learn from them and teach them the right way, and from us, teach them they are not invincible."
Mathew had been "truly thriving" in his new school and was loving its rigorous challenges, his father said. He was making outstanding academic progress and was looking forward to seeing his father in the next few weeks.
The packed funeral, conducted by Rabbi Hille Avidan at the Jewish Cemetery, Redhill, was attended by two busloads of pupils from Clifton College, including the school choir which led the national anthem.
Many surfing friends of Tomson - South Africa's legendary surfing world champion - who remain "shellshocked" by the tragedy swelled the number of mourners.
They joined the long line of grieving people waiting to offer their condolences to Mathew's devastated parents after the service.
Mathew, who returned from America for the start of the new school year, was an American citizen - as is his famous father who is based in the States.
Durban's United States Consul General, Eugene Young, also attended the service. Tributes from friends, relatives and teachers told of Mathew's dazzling smile, his "film-star looks," his love of sport, zest for life how he made friends easily and was "a real champion of the underdog".
Clifton College headmaster, Brian Mitchell, led the tributes by saying that although Mathew had only been at the school for a short time, he had a "real and lasting influence on all of us".
Mathew defined what appeared to be "cool and laid back".
Everyone knew him and "everyone liked him enormously ... He will always be part of our Clifton family."
With his voice cracking with emotion, school friend, Damien Roodt told how he had "lost a cool friend".
Mourners wept when Mathew's aunt, Leigh Winnick, sang Eric Clapton's Tears In Heaven.
An essay that Mathew wrote on the day of his death was read out and told of one of his favourite sports: surfing. Ant Brodowicz, a long-time friend of the senior Tomson, said the most powerful message to emerge was that parents should hug their children tightly.
"I was absolutely shocked at the state of Shaun and Carla. This is so sad," he said.
A memorial service will be held for Mathew at Temple David at 6pm on Friday. A police spokesperson said on Tuesday police were awaiting the results of a post mortem.