Greatest chin performance by a boxer?

Big George against Alex Stewart and Holyfield.

 

Hagler-Mugabi comes to mind.

 

Ray Mercer took bombs vs Lennox Lewis ..

 

I would say that indicates great resolve & a big fighting heart, with a great chin keeping you on your feet.

 

Holyfield hit Foreman flush well over a dozen times but George was going nowhere.

 

Recently rewatched Louis vs Baer thanks to the great quality video uploaded by @Pedro_El_Chef .

I know Max lost by knockout relatively early in the fight, but good lord he had Louis (perhaps boxings greatest puncher) unloading combinations on his dome, and he ate a lot before he finally did stay down. Louis was really moving his weight behind those punches too.

 

Thank you for the shout-out mate.
Regarding that fight, I'm surprised Max survived that counter barrage by Louis at the end of round 1.
He had already been hit with multiple hard left jabs, hook and cross combinations and then when Baer tried to take him out, landing a couple very hard shots on Louis, Joe turned it around and caught him with a massive right hand that buckled Max's knees. He nevertheless stayed up and took even more punches against the ropes.
To think he could go 3 more rounds taking those punches and be fully conscious at the time of the stoppage, just insane durability.