The following quote is from a Harry Greb biography.
Does anyone know any more about this clash of titans?When Greb was coming up and Jack Johnson was going down they boxed a four round exhibition in Kid Howards gymnasium in Chicago.
"It was a pleasure workin' with you, Jack," Greb said, and Johnson, the first Negro to hold the heavyweight championship, said, "Its almost impossible to set you up for a punch. You're the fastest man I ever boxed."