Douglas was his biggest defeat....People don't understand that before that fight, Mike was the biggest thing in sports...His fights were a event...That fight took away alot of Mike's Aura
Buster Douglas without a doubt, nothing is worse than the first loss and that loss was quite brutal considering the punishment Tyson took.
In terms of the physical punishment he took, the Lewis fight. His eye looked awful against Douglas but the laughable 'tools' the cornermen were using (a water-filled condom) to try to treat it didn't help. But the Douglas loss was the most damaging from a career viewpoint. Nothing was ever quite the same after that point, that did more damage to his career than any loss.
I voted for the Kevin McBride TKO loss where Mike just quit altogether against a journeyman. McBride is the worst fighter on that list.
I believe physically, it has to be Holyfield. Tyson admitted he was knocked out on his feet through most of the fight, with Douglas and Lewis he just got beat down, not knocked out, just counted out.
Buster busted him while he (tyson) and the world thought he was invincible. Buster just destroyed him and made him feel like he was on ***** street.