Anton Gilmore made an emotional but polished comeback at Emperors Palace in Ekurhuleni on Tuesday night.
Gilmore, 38, overwhelmed the young and talented but inexperienced Thompson Mokwana, 25, in every department over six rounds in the junior lightweight class.
The "Irish Terror" retired in 1997 after losing on points to Cassius "Hitman" Baloyi for the WBU super bantamweight title.
But Gilmore fulfilled the promise he made to his son that he would fight for him once only if the boy outlived doctors' predictions.
His son, Aidan, had 14 brain tumours and 10 heart tumors and doctors said he did not have long to live. He turns one tomorrow.
"That's it," said Gilmore announcing his final retirement.
His fight was one of the eight bouts of the Dingaan Thobela- Knockout Boxing Promotion box-and-dine tournament.
Diners gave Gilmore a standing ovation for his gallant decision as well as his fine display.
Toto Mubenga retired in his corner going for the fourth round without giving Reuben Groenewald a run for his money while Sipho Maabane went down like a bag of mealies in the first round against Victor Temlett, who made a resounding professional debut.
Mpumi Matshoba provided gritty opposition for Grant Fourie who dug deep to flatten Matshoba in the fifth round.
Bully "The Bulldozer" Muravha and Basil "No Apologies" Ray fought above themselves, but their poor conditioning turned their eagerly awaited heavyweight six rounder into a circus.
Muravha won on a majority points decision and earned the right to challenge Osborne Machimana for the national title. But Muravha is nowhere near ready for such a task.