LAS VEGAS — It’s the kind of fight Gennady Golovkin has been chasing from the moment he walked off an airplane six years ago to make his new home in Los Angeles.

It’s the fight boxing fans have been waiting for almost as long.

Golovkin and Canelo Alvarez meet Saturday night in a middleweight showdown that has been brewing for years. They do it in their prime, and they both bring the kind of power that could make for a night that will be talked about in boxing for years.

Three weeks after Floyd Mayweather Jr. and Conor McGregor met in an odd spectacle, boxing shows off its best side in a 12-round fight that will pay both men millions and make one of them the undisputed top 160-pounder in the world.

“It’s a true fight,” Golovkin said. “You can go back home or go to the hospital. It’s dangerous. Everyone understands that.”

Indeed they do, which is one reason Golovkin has had trouble getting fighters in the ring. Golovkin, a fearsome slugger from Kazakhstan, has stopped almost everyone put in the ring with him, winning all 37 of his fights, 33 by knockout.

But Alvarez also packs power and is a savage counterpuncher with a style that should match up perfectly against the onrushing Golovkin.

“I don’t back down,” Alvarez said. “I’m a counter-puncher and I like to fight.”

The combination of styles has fans salivating over what will happen in the same ring where Mayweather stopped McGregor three weeks ago. The fight quickly sold out and is expected to do well on HBO pay-per-view, though it won’t reach the level of last month’s hyped show.

Still, it promises to be a can’t-miss fight that brings back memories of the great middleweights of the 1980s. Both fighters weighed in Friday at the middleweight limit of 160 pounds.

“It all depends on who lands the punch that defines the fight and I think Gennady is going to do that,” said Abel Sanchez, Golovkin’s trainer. “They’re going to hit each other, and give fans the kind of fight they want and expect.”

It won’t be the first time the two have met but will be under far different circumstances. They sparred together at Golovkin’s camp in Big Bear, California, in 2011 when both were preparing for fights. Though accounts vary, both had their moments with each other.

But this is a real fight, with Golovkin’s titles at stake and a lot more. Both will make millions of dollars in a fight that holds risks – and plenty of rewards – for both of their careers.

“These are the fights that define your career,” said Oscar De La Hoya, who promotes Alvarez. “Both guys are not going to back down.”

Alvarez is arguably the most popular athlete in Mexico. Golovkin, who won a silver medal in the 2004 Olympics, hopes for the kind of performance that finally will win over fans not overly impressed by a 23-fight knockout streak of 18 middleweight title defenses.

Between them they have 86 wins and one loss. That was by Alvarez (49-1-1, 34 KOs) in 2013 against Mayweather – a fight he said he was too young to take.

Oddsmakers have made Golovkin a 7-5 favorite.