Jake Paul and Tommy Fury made weight today ahead of their showdown in Saudi Arabia on Sunday, when both men will put their unbeaten records on the line in a long-awaited contest more about celebrity bragging rights than punching prowess.

Heavyweight world champion Tyson Fury sported a keffiyeh headscarf and sunglasses as his half-brother Tommy weighed in at 184.5 pounds, half a pound under the cruiserweight limit, while Paul tipped the scales at 183.6.

"Tomorrow night his time is up, Jake Paul will no longer be boxing. I'm going to put Jake Paul away inside four rounds," a riled-up Tommy Fury said from the stage.

"He's acting on stage, getting all hyped up, trying to act like his brother. This professional boxer is going down. It's easy, it's simple. I'm ready - cool, calm, collected," Paul said, promising a finish in the same time-frame.

Mike Tyson at the press conference in Riyadh

After two previous bouts were cancelled, the pair will finally face off at the Diriyah Arena, where Paul expects a win against an unbeaten pro boxer with an 8-0 record that he hopes will burnish his reputation in the sport.

The brash Paul, a 26-year-old American best known for his social media videos, has disrupted boxing by taking on a series of fellow celebrities and ex-mixed martial artists en route to a 6-0 record, notching four knockouts along the way.

The 23-year-old Fury may have a more traditional boxing background behind his record, but he is more famous for his celebrity sibling and his career in British reality TV than his pugilistic skills.

"Like the posters say, the talk is over, we've done all the 'yeah, yeah, yeah', all the hoopla. It's time to figure out the truth," Paul said.

In the co-main event, Ilunga Makabu, 35, puts his WBC cruiserweight title on the line against Sweden's Badou Jack, 39, who is seeking a world title in a third weight class after previously holding belts at super-middleweight and light-heavyweight.