Andy Ruiz Jr produced one of the biggest shocks in the history of heavyweight boxing to rip Anthony Joshua's IBF, WBO and WBA world heavyweight titles from him and tear up the division's proposed plot lines.
In a truly remarkable fight at New York's Madison Square Garden, Ruiz floored Joshua four times en route to a seventh-round stoppage, which stunned this famous arena and handed the Briton his first defeat as a professional.
Joshua was a 1-25 favourite with bookmakers, with 22 wins - 21 by knockout - going into the fight. He will now join the likes of Lennox Lewis and Mike Tyson as dominant champions to suffer losses which brought the sport to a standstill.
"I got beaten by a good fighter," said 29-year-old Joshua on Sky Sports. "It will be interesting to see how far he goes, but this is all part of the journey.
"He's a champion for now, I shall return."
This was no fluke, no punch from the ages, it was the breakdown of a fighter who looked shattered from an early stage.
After flooring Ruiz with a left hook in the third round, Joshua hit the canvas when a right crashed against his temple. By the time a sensational three minutes was up he had been down again thanks to a flurry when cornered.
It created an electric buzz amongst the 19,000 or so in the arena. Just what was happening? Were they going to see the unthinkable?
Ruiz, 29, was not even supposed to be here. He took the bout at six weeks' notice and tickets were being collected by fans 24 hours before the bout which still had the name of Jarrell Miller - Joshua's original opponent - printed on them.
By the seventh round, when Joshua touched down under a flurry of shots again, the game looked up. Seconds later he was down on all fours again and spat his gum shield out, perhaps to buy time.
He simply did not have it. The bout was waved off and all that was planned for the glamour division was ripped up thanks to a man who had been dubbed unglamorous because of his rounded physique.
Ruiz, from appearance to pedigree, was an underdog in every sense of the word. When Britons wake up on Sunday morning, they will read of a truly iconic upset.