Los Angeles - Unbeaten Errol Spence and rival world champion Shawn Porter fight on Saturday in a welterweight boxing title unification bout with the winner looking at a possible 2020 showdown with Manny Pacquaio.
US stars Porter, the World Boxing Council champion, and Spence, the International Boxing Federation champion, meet at the Staples Centre in Los Angeles.
"The winner of this fight is definitely going to be the best welterweight in the world. There's no way around it," Spence said. "Being a unified champion and stamping my place in the division makes me even hungrier to win."
The card includes another all-American title showdown between WBC super-middleweight champion Anthony Dirrell and unbeaten ex-champion David Benavidez.
The Porter-Spence winner could face an early 2020 bout against World Boxing Association champion Pacquiao, the 40-year-old Filipino icon who stands 62-7 with two drawn and 39 knockouts and, like both US fighters, is promoted by Al Haymon.
"It's going to be a good fight, a close fight, but I think Spence will win," Pacquaio predicted.
Spence, a 29-year-old southpaw, is 25-0 with 21 knockouts as he prepares to defend for a fourth time the crown he took from British hometown hero Kell Brook in 2017 at Sheffield, England.
"I'm looking for the stoppage. I want to make a statement that I'm clearing out the division," Spence said. "I want Manny Pacquiao and all of the top names in this division."
Porter, 31, carries a mark of 30-2 with one drawn into his second defence of the title he took from Danny Garcia last September by unanimous decision.
"When I beat Errol Spence, it doesn't mean he's going away," Porter said. "But I'm going to take care of him and go after Manny Pacquiao. That's the plan."
Porter lost the IBF crown in 2014 to Brook, the first defeat of his career, and also lost to Keith Thurman in 2016 for the WBA title. But since then he has won four fights in a row, the most recent a split decision over Cuban Yordenis Ugas last March to keep his crown.
"I'm looking to make a statement by being the first person to knock Shawn out," Spence said. "It's important to me to get the knockout. It's a goal of mine to stop him."
Porter wants to drop Spence from the unbeaten ranks.
"I want to be the guy who beats him and takes his 0," Porter said. "I'm aggressive and I'm strong and guys can't handle it. I have the right recipe to get the job done Saturday. I have the style to challenge him physically and mentally."
Dirrell, giving up 12 years to his rival at age 34, took the vacant crown in February by beating Turkey's Avni Yildirim, improving to 33-1-1. His only loss came in his only prior title defence, also for the WBC crown, when he fell to Sweden's Badou Jack in 2015.
"Age is just a number," Dirrell said. "You see Manny Pacquiao and fighters like that who went out and beat younger opponents. You have to be determined and still focused on the game.
"Experience is definitely a big key in this fight. I think that he has holes in his game and I'm going to expose it on Saturday night."
Benavidez, 21-0 with 18 knockouts, was stripped of the super middleweight crown by the WBC after a positive doping test. He stopped J'Leon Love in his ring return last March.