Hearn's ranking comes at a time when the heavyweight division is as lively as it's been in years. In May, Usyk and Fury fought for the undisputed title, the first such bout in 25 years. Usyk won that fight, and the two are set to do it again in December.
In an interview with FightHype.com, Hearn explained his top five:
"AJ, obviously, Usyk, Fury, Parker, but Bakole could beat Parker. Parker is on a great run."
Joshua's return to the top spot in Hearn's eyes follows four wins after his losses to Usyk. He's now gearing up for a big fight against Daniel Dubois at Wembley Stadium. The fight is expected to draw a record crowd, with Joshua defending his IBF heavyweight title. Dubois earned his shot after stopping Filip Hrgovic and Jarrell Miller in his last two fights.
Joseph Parker grabbed the fourth spot on Hearn's list. The New Zealander has been on a strong run lately. Martin Bakole rounded out the top five, with Hearn suggesting he could potentially beat Parker.
Bakole's stock rose after a big win against Jared Anderson in August. Hearn expressed interest in seeing Bakole face Zhang, who's had a roller coaster of recent fights. Zhang stopped Joe Joyce twice, lost on points to Parker, and then knocked out Deontay Wilder.
Hearn shared his thoughts on a potential Bakole-Zhang matchup:
"I tweeted it, Bakole-Zhang. I love it, two absolute colossal lumps. I think Bakole beats him."
The heavyweight landscape is set to evolve over the next year. If competitive fights keep getting made, we'll get a clearer picture of who really deserves those top spots.