Francis Ngannou needed less than four minutes to render Renan Ferreira unconscious and celebrate an emotional return to MMA.
Ngannou was returning to the cage more than two years after his last outing, in which he defended his UFC heavyweight title against Ciryl Gane.
He then switched his attention to the boxing ring, giving Tyson Fury a huge scare only to slip to a points defeat, before he was brutally knocked out in the second round by Anthony Joshua.
The 38-year-old shed tears as he dedicated the victory to his late 15-month-old son Kobe, who passed away earlier this year.
“I can’t think about anything [other] than my son Kobe. I only took this fight because of him,” said Ngannou.
“I went to fight for him. I hope they can remember his name because without Kobe, we wouldn’t be here tonight. I wouldn’t have fought.”
Since leaving the UFC as its heavyweight champion 22 months ago, Ngannou has become one of the world’s biggest combat sports stars following blockbuster boxing bouts against Tyson Fury and Anthony Joshua.
But he has been adamant in the build-up to this encounter that he “never left MMA”, and always planned to fight again in the cage.
Ngannou considered retirement earlier this year, but said he had chosen to fight on in memory of Kobe as a way of “honouring him”.