Ruiz was born in California but fights under a Mexican flag by virtue of his parents’ nationality, and consequently became Mexico’s first-ever world heavyweight champion.
On Saturday he returned to Imperial, California, and flanked by a Mexican Mariachi band which paraded through the area where he grew up in the back of a convertible car.
It capped a “rollercoaster” three weeks since he floored Joshua four times to inflict a seventh-round stoppage and a first career defeat on a man who was a 1-25 favourite with bookmakers.
SalasDoePost earlier reported that Ruiz was a late replacement to face the Briton, and since the win has appeared on high-profile US talk shows, shown off his titles in Mexico City and seen his Instagram following rocket from 60,000 to 960,000.
He earned a reported $7m (£5.5m) for the bout. On Saturday, he told reporters: “First of all I bought a car for my mum, that was the first purchase I made from the money I got. I messed up a lot of her cars when I was young so I got her a brand new car.”
Joshua’s promoter Eddie Hearn has said his fighter seems keen to return to Madison Square Garden to avenge the defeat, which came on his much publicised US debut.
Ruiz who was at times ridiculed for his rotund physique in fight week vowed to weigh in lighter than the 268lbs he scaled before their original bout.
People thought I wasn’t going to do anything, I was too big, too overweight,” he added. “I don’t want to say all the things I am going to change.
There is going to be a lot of change, I am going to come at a better weight this time. It’s going to be a hell of a fight.”