Who would know. You can bracket a mob of guys like Lewis, Foreman, Liston, Tyson, Shavers and other favorites. Shavers should have been one of the first on the list. His overhand right overshadows the fact that he had huge power on every shot he threw and uppercuts were instrumental in the destruction of guys like Ellis and Norton.
Tyson Fury - even he wasn’t safe from it. Just as well that he could also take a great punch. This content is protected Otherwise, Foreman, Shavers and Lewis ring loudest. Prob with Earnie, even though his uppercut was a super power shot in its own right, he did hold the back of the head at the same time on more than a few occasions, including his marquee KO of Jimmy Ellis. Lennox Lewis did very much the same v Michael Grant.
Norton himself had a good right uppercut as did Larry Holmes. Joe Louis of course could throw anything well.
Tysons second round uppercut on Jose Ribalta is still most spectacular uppercut I've seen to this day Tysons uppercut that sent the 250 lb Buster Douglas flying was also devastating Of course I can't say with any certainty that he possessed the most powerful uppercut ... But it was the most incredible to behold...
Candy Slim Jeff Merritt had a very nasty uppercut. It’s hard to cite an uppercut that, although very powerful, was lacking in speed and style and was well telegraphed and likely avoided once he moved up to a certain level quality level of opposition. In this case, it was perfect for the very hittable Ron Stander. This content is protected
I mean are you willing to call Ruddocks uppercut/left hook hybrid an uppercut in this scenario ? If so Ruddocks smash punch against Dokes was terrifyingly powerful
If you count his "smash," as an uppercut,then Razor's.The two best , [not most powerful,] would be Johnson's and Holmes imo.
If hybrids are allowed then we can include Louis’ specific hook/uppercut that literally lifted 233 lbs of Galento off his feet, landing flat on his back, legs up in the air. Titanic shot.