No one gave Andy Ruiz Jr a chance.

Taking a fight against the 22-0 unified world heavyweight champion Anthony Joshua on six weeks' notice, the 29-year-old blocked out the doubters and got to work.

It was another opportunity for him to become the first ever heavyweight champion of Mexican heritage after an agonising majority decision loss to Joseph Parker for the WBO belt in 2016.

At 188cm and 121kg, Ruiz has often been overlooked by fans in the sport due to his image. It's an aspect he made sure to point out ahead of his bout with Joshua.

Advertisement

"Don't underestimate this little fat boy," Ruiz said in an interview with Sky Sports before the fight when asked if he had a message for his British opponent. "I'm coming for you, just tune in man, you're going down."

Under the bright lights of New York's Madison Square Garden on Sunday (NZ time), Ruiz stayed true to his word.

Andy Ruiz Jr is the first Mexican heavyweight champion. Photo / Getty Images
Andy Ruiz Jr is the first Mexican heavyweight champion. Photo / Getty Images

In what will go down in history as one of the biggest upsets in boxing history, Ruiz stopped the 198cm Joshua in the seventh round. After knocking Joshua down for a fourth time, the referee called a stop to the fight as Ruiz jumped around the ring in celebration.

"I wanted to prove everybody wrong," Ruiz said in his post-fight press conference. "All the doubters thinking that I was going to lose in the third round, first round, I was looking at comments (online) as well. But what do you know, man, I'm the first Mexican heavyweight champion of the world.

"Our lives are going to change. We don't have to struggle no more."

Ruiz looked to be in trouble in the third round of the fight when he was sent to the canvas for the first time in his career. He fought back in a strong way, though, and repaid the favour to Joshua.

Anthony Joshua sent Andy Ruiz Jr to the canvas in the third round of their heavyweight title fight. Photo / Getty Images
Anthony Joshua sent Andy Ruiz Jr to the canvas in the third round of their heavyweight title fight. Photo / Getty Images

Ruiz knocked Joshua down twice in the third round and twice more in the seventh before the fight was waved off.

"That's crazy that that happened right? That was my first time on the canvas. When I was on the canvas I was like, whoa what the hell just happened?

Advertisement

"I had to get him back. I think that was the Mexican blood in me, and the Mexican warrior that I have, I had to return the favour."

With a rematch clause in the contract, the two are expected to square off again in the UK later in the year. Anthony Joshua's promoter Eddie Hearn said his team would almost certainly be exercising that clause.

"It was an incredible night of boxing at the Garden, I'm sure everyone will remember it forever," Hearn said.

"I think Andy will fancy the rematch. He's just stopped Anthony Joshua...If he wins that rematch he really puts himself in position as, in my opinion, the golden goose of the division.

"Anthony, of course, has to accept that rematch. Knowing him I'm almost certain he'll want to do that."