Promoter Bob Arum believes whoever wins the Terence Crawford v Jeff Horn bout on June 9th will become top dog at 147lbs.

Horn makes the second defence of his WBO World Welterweight Title at MGM Grand in Las Vegas, live and exclusive in the UK and Ireland on BoxNation.

Last summer, the Australian won the belt after beating Manny Pacquiao in Brisbane in one of the upsets of the year. Now the former school teacher will relish being the underdog once again.

"If Horn wins it's a tremendous victory for him. He becomes the boss," Arum said to Horn's promoter Dean Lonergan. "He remains the Welterweight Champion and he goes into the records in boxing as one of the most elite fighters in the sport."

Crawford cleaned out the Super-Lightweight division after unifying four belts in August, beating the likes of Julius Indongo and Viktor Postol.

Even though this is his first outing at the weight class above, the Nebraska talent is a big favourite. However, Arum argues that Horn's physical and mental attributes give him a good chance.

"If you talk about boxing skills there's no question they belong to Crawford but when you talk about size, strength and determination you have to give Horn a very good chance," explained the 86-year-old.

"I don't know who will win this fight, a lot will depend on the determination of the two boxers. All I know is that it will be a good, hard fought competitive match. The winner of this fight will be considered the big superstar of the Welterweight division."

Errol Spence Jr currently holds the IBF World Title, with Keith Thurman holding the WBA 'Super' strap, so the winner could look to unify with either of those men later this year.

"If it's a great fight and Horn wins and agrees to fight Crawford in a rematch in Australia I'm sure Crawford would be amenable to that. [If Horn wins] a lot of elite fighters like Pacquiao and others will be knocking on his door looking to challenge him," added Arum.

Buy BoxNation to watch Terence Crawford v Jeff Horn on June 9th.