It's fun to imagine sound effects for this most elegant of leans. It's like he saw it coming two weeks earlier and made an appointment to dodge it.
I also like to pretend the ref has thoroughly mastered several dozen secret and deadly martial arts, and only didn't pull some insanely furious Fist Of The North Star shit on Holyfield because he knew the left hook was unintentional.
The second Holyfield decides to take another swing though, he's already dead.