Teddy Atlas says promotor Al Haymon likely will keep the belts in the family, having his own fighter Andy Ruiz Jr. take on one of his other clients, like Deontay Wilder. (1:10)

Opening Bell: Joshua-Ruiz autopsy

NEW YORK -- On an unforgettable night, Andy Ruiz pulled the gargantuan upset and turned the heavyweight division and boxing on its head with his stunning, shocking, utterly unexpected knockout victory over Anthony Joshua to take his three major world titles on Saturday at Madison Square Garden.

It was supposed to be a formality. Joshua was supposed to score a huge knockout that would serve as the launching pad for the British mega star to raise his profile in his United States debut at a hallowed arena, because if you can make it in New York, you can make it anywhere, as Sinatra once crooned.

Instead, it turned into this era's Buster Douglas-Mike Tyson upset, although not that big because Douglas-Tyson was not only the biggest upset in boxing history but also one of the biggest upsets in sports history.

The happy-go-lucky Ruiz, as likable a guy as there is, was given no chance to win by anyone, mainly because of a flabby body that doesn't exactly scream "heavyweight champion," and also because there was nothing on his resume that indicated he was capable of anything of this sort. In fact, his lone defeat, albeit by debatable decision, came against a guy, Joseph Parker, whom Joshua easily outpointed to unify belts in 2018.

But Ruiz made history by becoming the first boxer of Mexican descent to win a heavyweight title, and he did it impressively in a terrific fight that will likely be recognized as upset of the year. It featured the likely round of the year, because the third round was extraordinary, with Ruiz getting up from the first knockdown of his career to drop Joshua twice in a tumultuous three minutes.

Ruiz dropped Joshua twice more in the seventh round to finish him as the sellout crowd of 20,201 -- mostly Brits who had made the journey to cheer on Joshua -- seemed to go into shock. Ruiz had taken Joshua's perfect record and aura of invincibility along with it, not to mention murdering any chance of a Joshua showdown with Deontay Wilder for the undisputed title ever having the same kind of meaning as it would have had prior to Saturday.

That is because even if AJ should defeat Ruiz to reclaim the belts in a rematch for which he has the contractual right -- and one Matchroom Boxing promoter Eddie Hearn has pegged for November or December in the United Kingdom -- and were to go on to then face Wilder, it won't be the same because it will no longer be a summit meeting between undefeated titleholders at their best. That can never be recaptured thanks to Ruiz doing what he did.

Anthony Joshua is attended to while Andy Ruiz Jr. celebrates following Saturday's huge upset in New York. Al Bello/Getty Images

As an aside, this should be another lesson to the power brokers who refused to make Joshua-Wilder out of greed and because they didn't care what the public wanted. Joshua-Wilder goes by the boards in terms of the meaning it should have had the same way more recent in-demand fights, although not as big, also have: Vasiliy Lomachenko-Mikey Garcia, thanks to Garcia's one-sided loss to Errol Spence Jr. in March, and Jermell Charlo-Jarrett Hurd, thanks to both of them losing rather than facing each other. Let this also be a lesson to Spence and Terence Crawford to not wait too much longer to give the public their mega welterweight unification fight.

Saturday night was one no boxing fan will forget, nor will the fighters. For Ruiz (33-1, 22 KOs), 29, the son of Mexican immigrants from Imperial, California, it's the culmination of his hopes and dreams and a feel-good story.

"I wanted to prove all the doubters wrong who thought I was going to lose. Whaddya know? I'm the first Mexican heavyweight champion of the world," a smiling Ruiz, who was wearing a New York Knicks jersey, said at the postfight news conference. "It's a blessing. I'm still pinching myself to see if this is real, man."

It sure is, and he knows it, because he then shouted out his mother. "Mom, I love you. I love you, and our lives are gonna change," he said, referring to the millions of dollars he made Saturday and the millions more to come. "We don't have to struggle no more."

For Joshua (22-1, 21 KOs), 29, whose seventh title defense was anything but lucky No. 7, the questions are only beginning: Did he take the fight lightly? Does he need a new corner? Was he complacent? We don't know the answers yet. There was also heavy criticism, with hot takes such as these: He was exposed; he's got no chin, no stamina, and he quit.

On being "exposed": Those who go that route should be quiet and do a little homework by studying Joshua's record, on which they will see wins over quality heavyweights such as Wladimir Klitschko, Dillian Whyte, Joseph Parker, Alexander Povetkin and Carlos Takam.

On the chin question: Maybe he doesn't have a great one, but he's only ever been down against Klitschko (an all-time great puncher) and Ruiz, a 268-pound man who nailed him repeatedly on the button, and he kept getting up.

No heart? Everyone needs to relax. That he even made it out of the third round is a testament to his heart. Guys with no heart don't get up four times. And he was concussed, per a postfight announcement, so even though Joshua, whose legs were gone, said yes when asked by referee Michael Griffin if he wanted to continue after the second knockdown in the seventh round, Griffin read his body language and correctly stopped the fight because Joshua was done. There's a difference between being done and quitting.

play 2:23 Atlas: Ruiz 'just wrecked a hundred years of physical fitness' Teddy Atlas says that Anthony Joshua didn't look interested in the fight vs. Andy Ruiz Jr. and gives credit to Ruiz for catching Joshua behind the ear, throwing off his equilibrium.

All the Joshua critics should remember this: People said all the exact same things about fellow Olympic gold medalists Lennox Lewis, after he was knocked out by Oliver McCall and Hasim Rahman, and Klitschko, after his knockouts at the hands of Corrie Sanders and Lamon Brewster. It's easy to get caught up in the moment, but I'm looking at this long-term.

Lewis and Klitschko rebounded emphatically and went on to become all-time great heavyweight champions after their setbacks.

Now it's up to Joshua to see if he can do the same. He's a good guy (who doesn't deserve such harsh and mean-spirited criticism) and a talented fighter who has provided boxing fans with many big nights and exciting fights already. There are probably more to come, as he looks to digest the shock defeat and come back stronger.

Most of the media members left MSG after it was announced that Joshua would not appear at the postfight news conference because of a concussion. But more than an hour later, when he was being led out of the arena, he took matters into his own hands and went to the press area to face the music even though most of the reporters had left. It was his first step on his way to rebuilding.

"Trust me, I come from a good family, but where I was at in life [before turning to boxing], I dealt with more s--- than this," said Joshua, who made no excuses and gave Ruiz total credit for the victory (as did Hearn). "I've dealt with some real big losses and I've bounced back, and life is a journey. If I was to look at my setbacks back then, and I was to stop doing what I was doing, then I would've been f---ed. But I didn't do that. I kept my head strong, worked like a champion and I managed to bounce back.

"So, I feel like this is just part of a journey that I'm on. This is boxing, and what I have to do is re-evaluate the situation, make it better, and we go again. We didn't come this far to kind of stop. We didn't come this far to fold under pressure. We came this far, and I feel like we can definitely go a lot further."

Fights you might have missed

Saturday at San Jacinto, California

Welterweight Ivan Redkach (23-4-1, 18 KO) KO6 Devon Alexander (27-6-1, 14 KOs).

In the Premier Boxing Champions main event, Redkach, 33, a former amateur star from Ukraine fighting out of Los Angeles, scored an upset with an explosive knockout that may have finished off Alexander's career as a main event-caliber fighter. Alexander, 32, of St. Louis, a former welterweight and junior welterweight titlist, parted ways with career-long trainer and mentor Kevin Cunningham to train with Roy Jones Jr. in preparation for Redkach, who came into the ring being trained by another former pound-for-pound king, Shane Mosley.

Alexander, the better technician, was ahead 48-47 on all three scorecards going into the sixth round when the more aggressive Redkach took over courtesy of three knockdowns. He caught Alexander with an uppercut for the first knockdown, dropped the very unsteady Alexander again moments later and then for the third time with a barrage of blows, causing referee Thomas Taylor to wave off the fight at 1 minute, 10 seconds.

It's a career-best win for Redkach, who moved up to welterweight, and a disaster for Alexander, who badly missed weight (coming in at 151.5 pounds) and dropped to 1-4-1 in his past six fights.

Middleweight Willie Monroe Jr. (24-3, 6 KOs) W10 Hugo Centeno Jr. (27-3, 14 KOs), scores: 98-92, 97-93, 96-94.

Monroe, 32, a southpaw from Rochester, New York, was supposed to challenge Jermall Charlo for his interim middleweight world title on Dec. 22, but Monroe was dropped from the fight five days earlier for testing positive for a banned substance in a random drug test. So, in his first fight in 10 months, Monroe, who has lost world title fights to Gennady Golovkin and Billy Joe Saunders, returned to face Centeno, 28, of Oxnard, California, and handed him his second loss in three fights.

Monroe took control from the outset, bloodied Centeno and used his slicker boxing skills to earn the decision, which was surprisingly close on one of the scorecards.

Saturday at Macau, China

Light heavyweight Meng Fanlong (15-0, 9 KOs) W12 Adam Deines (17-1-1, 8 KOs), Title eliminator, scores: 117-109, 116-110, 115-111.

Fanlong, 31, of China, earned a mandatory shot at world titleholder Artur Beterbiev with his victory over fellow southpaw Deines, 28, of Germany, which came on a card that took place during the IBF annual convention at the Wynn Palace. In an otherwise slow-paced fight, Deines had his best moment in the eighth round when he scored a knockdown, but Fanlong was a bit busier and did a bit more to earn the nod from the judges.

Deines also hurt his cause when he hit Fanlong on the break in the 12th round, prompting referee Eddie Claudio to penalize him one point.