There is a good reason why American boxing fans and followers of Deontay Wilder should be cheering on Anthony Joshua on Saturday.
Wilder's biggest rival might be Joshua, but the WBC world heavyweight champion and his supporters will be wishing Joshua well in his three-belt unification showdown with Joseph Parker at Cardiff's Principality Stadium.
WBA-IBF champion Joshua is boxing's biggest star, attracting television audiences from all over the world with earnings of $15-$20 million per fight. He is also the sport's most marketable figure and biggest crowd-puller, with 80,000 expected for the clash against Parker. In his two previous fights against Wladimir Klitschko and little-known Carlos Takam, Joshua was watched by audiences of 90,000 and 78,000, respectively.
A showdown against Joshua, for all four world heavyweight title belts if the Englishman defeats New Zealand's WBO titleholder Parker, would be Wilder's best career payday by far.
It would also be arguably the biggest fight in boxing this year, eclipsing the middleweight rematch on May 5 between Gennady Golovkin and Canelo Alvarez.
For that reason, fans around the world will want Joshua to extend his unbeaten record against Parker, who does not generate anything near the same international interest or revenue.
Joshua and Wilder are both knockout specialists whom fans love to watch. Joshua, 28, has knocked out all 20 professional opponents, while Wilder, 32, has taken out all but one of his 39 professional opponents.
They have also both won Olympics medals: Joshua won gold in 2012; Wilder bronze in 2008.
A shock defeat for Joshua, who is a big 1/9 favorite with UK bookmakers, would end the exciting prospect of him fighting Wilder in the near future.
It would also be costly for Wilder, who made a seventh defense of his belt against Cuba's Luis Ortiz at Barclays Center in Brooklyn earlier this month.
The Alabama boxer would earn far more from facing Joshua than Parker.
Joshua-Wilder would be boxing's most significant matchup between two reigning world heavyweight champions since Lennox Lewis, who was born in London but moved to Canada aged 12, fought American Evander Holyfield twice in 1999.
It is uncertain whether victory for Joshua this weekend will set up boxing's first four-belt world heavyweight title fight for later this year.
Joshua's promoter Eddie Hearn has talked about taking AJ to America for the first time in his professional career, possibly against Jarrell Miller at Barclays Center in Brooklyn in August or September.
That would increase interest in Joshua in the United States and strengthen his position at the negotiating table with Wilder. Hearn has scoffed at Wilder's insistence on a 50-50 split and argues Joshua has a larger profile so deserves a bigger chunk of the money.
But there is still plenty of time to iron out a deal, as Joshua may also have to make a mandatory defence, possibly against Russia's Alexander Povetkin (No 1 with the WBA and WBO) who fights England's David Price on the undercard in Cardiff on Saturday.
A wait would only increase anticipation and mainstream interest. No matter who your allegiances are with, most fight fans want to see Joshua versus Wilder.
But if Parker upsets the odds, that dream fight moves further from reality.