LAS VEGAS — His words, just 22 simple but to-the-point words sent to the world in a tweet, say everything that needs to be said about Gennady Golovkin as he awaits the biggest night of his life.

Thursday, on his verified Twitter account, Golovkin wrote, “If you go in the ocean, the shark knows. He’s home. It’s the same for me in the ring. … Let’s do it.”

Golovkin is the undefeated WBA, WBC and IBF middleweight champion, who has 33 knockouts and 37 wins in 37 fights and who, at more than seven years covering 18 defenses, is boxing’s longest-reigning title-holder.

Validation wouldn’t come, though, by smashing a trail of palookas and tomato cans.

He knew it, too, knew that he had to face that special opponent, that one man who had the ability to not only survive his powerful blows, but to return fire with similar force.

Long ago, years before this fight was made, Gennady Golovkin knew he needed Canelo Alvarez.

He needed the Mexican superstar to vindicate himself as more than a bully, to earn the respect so that his name was spoken reverentially by the historians alongside those of men named Hagler and Monzon and Robinson and Greb.

He needed the freckle-faced redhead to validate his many achievements, to put the lingering doubts about the caliber of his opposition forever in the past, to answer the questions that can only be answered by staring down one of boxing’s best.

And so, somewhere around 8 p.m. local time Saturday at T-Mobile Arena, the Kazakh Killer will slip between the ropes and will, after the anthems are sung, the celebrities in their fancy clothes take their seats and the ring is finally emptied, tear after his soon-to-be friend to answer a question the boxing world has asked for several years now:

Is Gennady Golovkin one of the greatest middleweights who ever lived?

That 37-0 record, those 33 knockouts and that Olympic silver medal provide proof, though not irrefutable or conclusive, that he is.

So, too, does that trail of bodies that lie in his wake. He cracked three of Matthew Macklin’s ribs with one of the sweetest hooks to the body you’ll ever see. The sound of Macklin shrieking in pain won’t soon be forgotten by those who were there to hear it.

He shattered Kell Brook’s face with the force of his fists. He punctured Daniel Geale’s spirit, stole Willie Monroe’s soul, with his ferocious, unstoppable power and intensity.

He’s as affable and accommodating as one could expect an athlete of his caliber to be, except for that hour before the fight until the time his arm is raised, when he somehow changes from Gennady to Triple-G.

Triple-G understands that boxing is a war of attrition and a dangerous game. It changes lives, he said, with the single thwack of a 10-ounce glove.

“One punch can change your life,” Golovkin said. “Because of my power, I see it all the time from my work with my sparring partners. Sometimes I see what happens. So many people are hurt in fights. … This is not a game. Go too far, you know you’re not going back home, you’re going to a hospital. Everybody understands that.”

By the end of 2009, five years into his professional career, Golovkin was at his wit’s end. After earning a silver medal in the 2004 Olympic Games in Athens, he turned pro and won his first 18 bouts, 15 by knockout.

He knew, his managers knew, that something wasn’t right. The big fights, the ones he really wanted, weren’t happening. He was based in Germany and the big fight at the time was with Felix Sturm, but Sturm was none too interested in fighting this monster without a massive reward.

Managers Oleg and Max Hermann reached out to Tom Loeffler, the promoter for K2, whom they had known for his good work in helping the Klitschko brothers in Germany.

Golovkin was going to come to the U.S. and needed a fresh start, including a new trainer. Loeffler, who is based in Los Angeles, recommended three Los Angeles-area trainers: Freddie Roach, Robert Garcia and Abel Sanchez.

Roach and Garcia were the hot names. Sanchez had long been one of the game’s better trainers, and he’d guided Terry Norris to world titles, a win over Sugar Ray Leonard and a spot in the International Boxing Hall of Fame. But Sanchez had kind of moved on and was largely working in his construction business.

Roach and Garcia made the most sense.

But when Golovkin met Sanchez, the search was over.

“Abel, he was the right man for me,” Golovkin said.

Sanchez picked apart his style, rebuilding it almost from the ground up. He taught him to attack, to move forward effectively, to use the natural power in his fists most efficiently.

Golovkin took to it expertly, and they immediately racked up the wins and the knockouts. But as the total in each column rose, so, too, did the reluctance of other elite fighters to face him.

Golovkin was, in one regard, like the popular ex-heavyweight champion Mike Tyson: He punched frighteningly hard, and had no compunction about battering a wounded opponent with vicious shots until the referee pulled him off.

Unlike Tyson, though, he wasn’t well known and fights against him weren’t that lucrative. Heavyweights in the 1980s and 1990s sought out matches against Tyson because they’d make the biggest purse they could ever get. But such was not the case with Golovkin.

Alvarez, who most decidedly was not afraid, didn’t take the fight at first, either. Promoter Oscar De La Hoya chose to repeatedly put it off, matching Alvarez with Amir Khan, who had been knocked out at lightweight; Liam Smith, who never had a prayer of winning; and Julio Cesar Chavez Jr., a talented but enigmatic fighter who usually fought like he didn’t give a darn and was willing to take a beating for a check.

Unhappy, Golovkin was left to fight opponents he wasn’t all the interested in. He tired of the relentless questions about when he’d fight Alvarez, of showing up at an Alvarez bout and being used as a prop.

But with nowhere else to go, the fight to make was Alvarez-Golovkin, and De La Hoya quickly put it together with Loeffler. Despite the Floyd Mayweather-Conor McGregor fight on Aug. 26 that stole much of the attention that would have gone to Alvarez and Golovkin, the fight remains very much a big deal.

The pay-per-view is tracking well and will certainly exceed 1 million, and could reach as high as 1.5 million. Every seat will be filled at T-Mobile Arena, with rabid boxing fans awaiting what could be the finest fight in the middleweight division since Marvelous Marvin Hagler and Thomas Hearns put on an all-timer in 1985.

Golovkin knows what is at stake. In some ways, his career is on the line. Lose, and he’ll be viewed by many as just another belt-holder in an era overrun by four or more “champions” per division.

He needs to fight at range, and keep Alvarez on the end of his pulverizing jab. He needs to whip shots to the body. He has to constantly pressure, look for openings and exploit those that come.

But, as he writes, he is the shark and this is his ring. He knows what is at stake. He knows what he must do.

In a fight for the ages, Golovkin ends all doubts and finishes it in nine.

More GGG-Canelo coverage from Yahoo Sports:
• Why GGG-Canelo will go down in the history books
• Canelo Alvarez faces make-or-break moment
• Golovkin-Alvarez bout to decide ‘new face of boxing’
• Gennady Golovkin is ready to seize the biggest moment of his life