LAS VEGAS — Just the idea of a big 160-pound fight had promoter Bob Arum reminiscing about the 1980s, when Marvelous Marvin Hagler and Thomas Hearns took on all comers and middleweights ruled the boxing world.

Saturday night’s fight between Julio Cesar Chavez Jr. and Sergio Martinez isn’t exactly Hagler-Hearns, but it is intriguing enough to get boxing fans excited about the middleweight division again.

Chavez defends the piece of the 160-pound title Martinez believes should still be his when they meet in a fight that seems quite personal to both. There’s a good chance the fight could turn into an old-fashioned brawl, the prospect of which was enough to sell out the 19,000-seat UNLV campus arena.

Chavez Jr. is fighting to escape from the shadow of his father, the legendary Julio Cesar Chavez, and establish himself as one of the new stars of the sport. Martinez is trying to solidify his position as the best middleweight in the world, and dispatch a fighter he doesn’t think even deserves to be in a title fight.

“It will not be an easy knockout,” Martinez said. “I will punish him a lot and after that I will knock him out.”