George Chuvalo is a Canadian former professional boxer who was a
five-time Canadian heavyweight champion and two-time world heavyweight
title challenger. Chuvalo is known for having never been knocked down
in his 93 bout professional career including fights against Muhammad
Ali, Joe Frazier, and George Foreman.
https://boxrec.com/en/proboxer/119​

https://boxrec.com/en/proboxer/119