Just like Tyson vs Douglas in 1990, Lewis vs McCall in 1994 and Lewis vs Rahman in 2001, Joshua's defeat at the hands of the unheralded Ruiz Jr will reverberate through boxing like no other shock result for years to come. No-one but Ruiz Jr's, his trainer Manny Robles and close family and friends gave the American of Mexican descent any chance of pulling off the win.
At most, Ruiz Jr had 5 weeks to prepare for this fight, easily, the biggest of his career, and although boxing insiders knew that the Californian possessed quick hands, a high boxing IQ and the experience of 105 amateur bouts and 33 pro bouts, Joshua's credentials trumped his on every level.
Ruiz Jr's blubbery physique has always been seen by many as a reason why he could not succeed at the highest levels, and yet history had taught boxing historians that underestimating a less than herculean opponent could go wrong for even the best heavyweight champion.
In 1939, champion Joe Louis took on "Two Ton" Tony Galento, a barroom brawler who looked incapable of lasting a single round with the phenomenal "Brown Bomber." Galento was as wide as he was tall, but he had a devastating left hook. After being knocked down in the 1st round Galento floored Louis in the 3rd, and even though "The Brown Bomber" came back to stop "Two Ton" in the 4th round the lesson was there for the future champions to heed.
Although born in California, Ruiz Jr will go down as the first Mexican heavyweight champion of the world, a fact that he had brought to the attention of anyone willing to listen in the build-up to the fight. But it is how the win has altered the landscape of the heavyweight division that is the biggest achievement for Ruiz Jr.
In fairness to Joshua, the media asked very few questions in the build-up regarding how he would deal with his late replacement opponent compared to when he would be fighting WBC champion Deontay Wilder. Wilder detonated the news that he would be re-matching Luis Ortiz and then Tyson Fury in a 24 hour period that just happened to coincide with the weigh-in and final press conference of the Joshua vs Ruiz Jr fight. All schemes to take Joshua's attention away from the job in hand.
But no matter what transpired before the fight, it is only what took place after the first bell sounded that will be recorded in boxing's history books and that reads: Andy Ruiz Jr Tko round 7 vs Anthony Joshua.
Welcome to the bigtime Champ.