By Harry Allison

There’s plenty on the line when Gennady Golovkin and Canelo Alvarez step into the ring tonight in Las Vegas.

To the man who raises his hand in the end, though, goes something much bigger than a belt or paycheck.

“The winner of this fight earns the position to be the face of boxing,” Philly’s Bernard Hopkins, who won a closetful of belts and was one of the top fighters of his generation, told the Washington Post. “He can be what Ali was, what Mike Tyson was, what Oscar was. It’s not just about being a champion, it’s bigger.”

While last month’s fight between Floyd Mayweather Jr. and Conor McGregor, the UFC star, generated worldwide attention and was a bona fide pop culture event, most in boxing regard tonight’s showdown as the sport’s marquee event of the year — the “real fight,” as everyone involved keeps saying.

It’s not a totally unfamiliar place for Alvarez. He’s been on this doorstep before, a champion knocking on the door of next-level success and fame.

“I’m writing my history now,” he said this week.

The lone blemish on his sterling record (49-1-1, 34 knockouts) is impossible to skip over. He’s beat Shane Mosley, Miguel Cotto and Amir Khan. Those victories showed the boxing world what he is — a great champion and a generational talent. But his 2013 loss to Mayweather showed everyone what he isn’t — or at least what he wasn’t at the time — a transcendent fighter who could carry the sport on his shoulders.

Surely, there’s no shame in losing to one of the best fighters ever, but Alvarez and his camp are quick to point out that a lot has changed. The Mexican-born boxer was 23 years old then, fighting Mayweather when other foes could barely lay a glove on the five-division champion.

“He did take that fight too soon,” said Oscar De La Hoya, whose Golden Boy Promotions handles Alvarez’s fights, “but the progress that he has made has been incredible.”

Since then, Alvarez’s power is stronger and his jab more effective. He steps into the ring with more confidence and the ability to dictate the tempo against anyone. Both Alvarez and Eddy Reynoso, his longtime trainer, said he’s “more of a complete fighter now.”

“He’s 100 percent of a different fighter than the fighter that faced Mayweather,” the trainer said.

“I’m more of a mature fighter now … I’ve changed and I learned from it,” Alvarez said.

This represents his toughest challenge since then. While Mayweather would set traps and lull foes into mistakes, Golovkin (37-0, 33 KOs) charges ahead with power the middleweight division has rarely seen. He has an impressive pedigree, extensive amateur background and perhaps the best jab in boxing. Making matters tougher, Golovkin doesn’t hurt easily and has never been knocked down, not as a professional and not as an amateur.

For his part, Alvarez also has never been knocked down and he also has the power and balance that make boxing trainers drool. Oddsmakers list Golovkin as a slight favorite but many in the boxing world consider the bout a virtual coin flip, a matchup that could help energize the sport and evoke memories of the glory days of one of boxing’s most storied weight classes.

“On paper, obviously, it’s going to rival some of those big fights … but it really depends how the fight comes out, how it pans out,” Alvarez said. “I’m going to do my part to make it memorable so I can go down in history as one of the best fighters.”

De La Hoya’s era included champions like Felix Trinidad and Hopkins, who’s a partner in Golden Boy. Back then, fight fans regularly felt they were seeing the best against the best. By comparison, Saturday’s bout took two years and plenty of public hand-wringing to make.

“I want to win this fight,” Golovkin said, “because maybe for me this win will be like a history fight, like [Sugar Ray] Leonard vs. [Marvin] Hagler. Like middleweight division, I believe the boxing division will come back.”

De La Hoya doesn’t shy away from hyperbole, calling the bout the biggest the division has ever seen. Granted, as a promoter he has a huge stake in the Saturday’s card and plenty of reason to assert such things, but he says the fight is even bigger than the middleweight clashes of the 1980s, a period that included Leonard, Hagler, Thomas Hearns and Roberto Duran all battling it out.

“I mean obviously we have to wait for the actual fight to see what unfolds and takes place,” De La Hoya said. “But in terms of magnitude, in terms of PR, in terms of attention that it’s receiving, in terms of people that will be watching, yeah, this has to be the biggest … It has all the ingredients to unfold to be one of the best fights in the last 30 years.”

It’s certainly the biggest since Mayweather fought Manny Pacquiao, and given the boxers and styles involved, many expect a more memorable fight — certainly one with bigger stakes for the sport.

Boxing has waited a couple of years for the matchup, but both fighters feel they’ve been waiting longer. While Golovkin has had trouble getting top-tier opponents in the ring with him, for Alvarez, the fight represents something different. It won’t erase the Mayweather loss, but it could supersede it in a sense. A win on Saturday could finally anoint him as the kind of champion boxing has been seeking, the type of personality and marketable star who can serve as the face of an otherwise faceless sport.

“When I was a young boxer starting out, of course you never imagine all of this coming true,” Alvarez said this week. “However, in my heart, I’ve always wanted this, and I’ve always dreamed of the day in which my discipline would pave the way to where I am.”