The Mexican sent shockwaves throughout the world of boxing on Saturday night as he dropped Anthony Joshua four times en route to an improbable seventh-round knockout.
Ruiz, who came into the fight as a late replacement for Jarrell Miller, claimed the WBA, WBO and IBF world heavyweight titles with the win.
The fighter known as ‘The Destroyer’ became Mexico’s first ever world heavyweight champion, and will rematch the Briton later this year.
Despite being laughed at by a number of fans before the fight due to his less-than-athletic physique, Ruiz put in a brilliant performance to bounce back from being dropped for the first time in his career in the third round.
Joshua landed with a perfect uppercut and left hook to drop the underdog, but Ruiz took his time before getting back up.
And once he rose from the canvas, he wasted no time in unloading his fast hands and dropped the champion twice in the same round.
Joshua never fully recovered, and was waved off by the referee after two more trips to the floor in round seven.
Ruiz’s pre-fight 12-1 odds led many to believe that the fight was a foregone conclusion, but the challenger revealed on the Bill Simmons podcast that he and his family always had faith.
Speaking on the podcast, Ruiz revealed that his whole family placed money on him winning the fight, but he was not keen on doing the same.
“My whole family bet on me, I wanted to but I didn’t want to jinx it,” he said.
“Of course I was confident I was going to win, but I didn’t want to put money on it and stuff.
“My parents won like $10,000 each, my little brother won $7,000.
“Maybe I should have done that too.”
Ruiz will now face Joshua in a rematch towards the end of the year, after the former champion’s team exercised an immediate rematch clause.
According to reports, Joshua will have the choice of venue for the return bout, meaning the fight is likely to take place in the UK rather than see the 29-year-old take another trip to America.