One judge had Anthony Joshua ahead after six rounds before he was brutally beaten by Andy Ruiz Jr.
The British star, 29, suffered one of boxing’s biggest shocks when the referee brought an end to the bout in the seventh, The Sun reports.
AJ looked knackered and had already been dropped earlier on, including twice in the third round and then twice in the seventh.
Ruiz, 29, was bossing the fight and had the better of Joshua for the majority of the fight.
But while Michael Alexander and Julie Lederman both had Ruiz 57-56 ahead on their scorecards after six rounds, Pasquale Procopio somehow had the Watford man 57-56 up.
Procopio had AJ down as winning the first, second, fourth and fifth rounds.
According to Procopio, Ruiz had only won the third — by a score of 10-8 following the two knockdowns for AJ — and sixth.
But then Ruiz came out of the blocks flying at the start of the seventh.
He sent the WBA, IBF and WBO king crashing down to the canvas and although Joshua got back up again, moments later he was back on the floor.
And as Joshua recovered in the corner, referee Mike Griffin had seen enough and called it off — AJ was beaten for the first time in his career.
The humble Ruiz said: “This is what I’ve been dreaming about. I’ve made my dreams come true.
“I just thank God so much. I’ve got that Mexican blood in me.”
Defeated Joshua added: “I just got beaten by a very good fighter tonight.
“He’s a very grounded fighter and congratulations to the first Mexican heavyweight champion.”
On Twitter, some fans and commentators could not believe Procopio’s scorecard.
“Are we really gonna ignore the fact the judges had that fight mad close on the scorecard,” boxing fan @TheGoatest1 wrote on Twitter.
“I honestly don’t know how they had that fight as close as the commentators mentioned.
“It felt like Ruiz won 4/5 of the 6s rounds at least.”