LAS VEGAS -- When Duco Events promoter Dean Lonergan signed Jeff Horn after he made a run to the quarterfinals at the 2012 Olympics, he and Horn trainer Glenn Rushton sat down to map out his career.

The plan they followed has worked out quite well for Horn, who is now an undefeated welterweight world titleholder who last July pulled off one of the biggest upsets in recent boxing history.

That was when Horn, fighting before a hometown crowd of more than 50,000 at Suncorp Stadium in Brisbane, claimed the belt by decision, albeit a controversial one, against Manny Pacquiao.

Now Horn, who is making his second title defense, is aiming for what would be another monumental upset. He's facing Terence Crawford, the former lightweight world champion and former undisputed junior welterweight champion, who is moving up in weight to challenge Horn on Saturday night (ESPN+, 9:30 ET) at the MGM Grand Garden Arena.

"Glenn had a very big vision for Jeff," Lonergan said Thursday at the final pre-fight news conference. "Vision one was that one day we're going to fill Suncorp Stadium with 50,000 people for a mega fight and then we're going to go on and conquer the world. And the first part of that equation we managed to achieve. We put together a fight thanks to [Top Rank promoter] Bob Arum and the Queensland State government where we managed to bring one of the best fighters of all time down to Queensland in front of 51,000 and managed to take away the belt."

Lonergan said he expects another upset Saturday night.

"We knew the Top Rank matchmakers made a mistake putting [Pacquiao] in with Jeff Horn, and it turned out that that was the case," he said. "We think Top Rank again erred, and the matchmakers have put Terence Crawford in with the wrong guy, and we're going to find that out on Saturday night. Terence and 'BoMac' (Crawford trainer Brian McIntyre) obviously have different ideas, and it's going to be interesting to see what happens on Saturday night because one of us is right."

Crawford (32-0, 23 KOs), 30, of Omaha, Nebraska, has been a dominant force in boxing for the past several years and is viewed as one of the best fighters in the world pound for pound, if not the very best. He was the 2017 ESPN fighter of the year and in August became only the third fighter of the four-belt era to unify all four major sanctioning body titles when he blitzed Julius Indongo in a third-round knockout to take his two belts and become the undisputed champion at 140 pounds. Now Crawford is moving into the talent-rich 147-pound division, with Horn (18-0-1, 12 KOs), 30, who is making his American debut, standing in his way.

"He's viewing me as a small welterweight, and come fight, he's going to see otherwise," Crawford said. "He's coming in hungry and determined, and that makes for a good fight. I'll be prepared for whatever he brings come Saturday, and he might get hurt.

"I'm not Manny Pacquiao. I'm bigger. I'm stronger. I'm in my prime, and that's going to show come Saturday. We'll see Saturday night who's getting rocked and dropped. This is what everybody's been waiting on -- for Terence Crawford to move up to 147. I'm looking forward to putting on a great show come Saturday night."

Said McIntyre: "He's going to stop [Horn]. I have all the confidence in the world in Terence. I really only got one word to say -- it's the takeover, and Jeff just happens to be there to be the first victim."

The Horn camp had a vastly different opinion.

"We think Jeff Horn is the bigger, stronger guy. We think he's the biggest, strongest welterweight in the division, full stop," Lonergan said. "He showed that against Manny Pacquiao.

Horn said he plans to be on his flight home to Australia still in possession of his title.

"I'm surprised I'm as big of an underdog as I am for the fight," Horn said. "I am not surprised that I am the underdog. Terence is a great fighter. He's pound-for-pound. He wiped out the [junior welterweight] division, and that's a tough division as well. I know he's put on the size, and he's going to be a nice strong welterweight.

"I can't wait to get in there and prove the doubters wrong. I've heard I'm a chump. I've heard I'm a fraud. I'm just there to prove everyone wrong."