Active heavyweights beaten by one man only

[JakeTheBoxer]

Joshua lost only against Ruiz.
Wilder lost only against Fury.
Kownacki lost only against Helenius.
Pulev lost only against Klitschko.
Ortiz lost only against Wilder.
Whyte lost only against Joshua.

So this guys have something in common. They lost against one man only. But still, it is discussed like "yeah, everybody can beat him, because that man did". But is it so?

[Mammoth]

Bakole and Kuzmin only lost to Michael Hunter

Michael Hunter only lost to Usyk

Oscar Rivas only lost to Dillian Whyte