Boxers KO'd by the sparring partner..

[Hulk]

Kid Diamond hurt PBF but then again I doubt how much stock can be placed with that on account of Floyd's sparring sessions sometimes include 10-12 minute rounds so PBF might have been at the end when The Kid did his thing.

Foreman sparred with Liston, don't know if he ever KO'd him though

I would be interested to hear more about those sessions between Sonny and George.