LAS VEGAS — Dmitry Bivol pinned Canelo Alvarez on the ropes in Round 5 on Saturday and unleashed a six-punch combination, most of which landed flush.

This was a rare sight, the pound-for-pound king vulnerable and in real trouble. It’s dangerous to throw that many punches in succession against such a gifted counterpuncher, but Bivol let his hands go during that round and really all night … and never paid for it.

Bivol (20-0, 11 KOs) wasn’t simply too big for Alvarez; he was too good. His precise punching, excellent footwork and jab were far too much for Alvarez to contend with in his second 175-pound title bid.

Most of all, perhaps, Bivol’s temperament won the fight. Most Alvarez foes appear defeated before they even step through the ropes, but the 31-year-old Russian exuded confidence all fight week. The moment never seemed too big, and now he’s scored a life-changing victory, even if the judges attempted to steal it from him.

“When I heard the scores of 115-113, I thought, ‘Maybe I lost today,’ but I feel I won,” Bivol said. “I expect that. Everything against me today.”

When one faces the sport’s biggest star, the deck is typically stacked against them. “No rules for him,” Bivol said.

ESPN scored the bout clearly in Bivol’s favor, with many similar scorecards from around the boxing world offering up 118-110 for Bivol or, at worst, 117-111. But the judges incredulously scored the first four rounds for Alvarez, a clean sweep. Bivol needed to win the 12th round on all three cards to avoid a draw and move on to a potential rematch.

The Mexican star indicated he planned to exercise his right to an immediate return bout, but it’s hard to see what adjustments he can make to solve the Bivol puzzle.

“Canelo against Dmitry Bivol 2 is probably the biggest fight in boxing now,” said promoter Eddie Hearn. “I can’t see [Alvarez] not wanting to accept the challenge.”

Bivol was all-in on facing Alvarez again: “Rematch? No problem.”

The upset victory — Bivol was a 4-1 underdog, per Caesars Sportsbook — may have spoiled plans for a Sept. 17 trilogy bout between Alvarez and Gennadiy Golovkin.

Now, it could be the date Bivol looks to cement himself as one of the 10 best pound-for-pound boxers in the world. Bivol is sure to crash the list in the aftermath of the win. He was earmarked for this lofty recognition all along, ever since buzz surrounded his ShoBox debut in 2017.

Bivol captured several gold medals in international amateur tournaments and exited the unpaid ranks with a 268-15 record. He’s replicated that success in the pros — you’ll be hard-pressed to find a round he lost — and that didn’t change against the best fighter in the world.

The issue for Bivol all along was that he was avoided by many of the best boxers at 175 pounds. He was unable to get the big fights and, as a result, unable to showcase his full arsenal of skills. But even after the crowning achievement of his career, he still doesn’t see himself as the world’s best light heavyweight.

“I don’t feel it because I don’t have all the belts,” he said. “My dream is to be the undisputed champion.”

Bivol holds one title, and a man he already defeated, Joe Smith Jr., holds another. Artur Beterbiev owns two titles and is set to unify with Smith on June 18 on ESPN.

A fight between Bivol and the winner of that fight would crown an undisputed light heavyweight champion. Beterbiev is heavily favored in that bout.

Vadim Kornilov, Bivol’s manager, told reporters that Bivol and Beterbiev were in negotiations for a May bout in Russia, but talks were halted because the date wasn’t suitable for Beterbiev, who observes Ramadan.

Then the opportunity to fight Alvarez presented itself. Still, there were detractors of the fight since Bivol is Russian and other sports have prevented Russian athletes from participating in events due to the ongoing crisis in Ukraine.

“I’m really sad that people who like me … I just do only boxing, boxing, boxing, and then you can’t do boxing,” said Bivol, who condemned the war. “You can’t be somewhere and show your skills. It’s really sad that it’s happening. It’s like if someone tells you you can’t do your job.”

But Bivol was able to push through and capitalized with the sort of win young boxers dream of. He showed his personality this week after choosing to often speak through a translator in the past, and he has a chance to become a star in his own right in the mold of another Eastern European fighter who’s competed with Alvarez.

Bivol doesn’t possess GGG’s power, but his boxing skills are among the best in the world, and his one-liners aren’t too far behind.

“He kept hitting me in the arms and I kept hitting him in the face,” Bivol said. “Eddie Hearn, sorry I broke your plans with Gennadiy Golovkin.”