Fighters that were shot in their 20s

[El Kabong]

I was going to post Tyson but he won titles AND was at least top 5 after 1990, he wasn't really shot until he was 30 when he lost to Holyfield twice and even then he was still able to win a title here and there.

There have been any number of heavyweights other than Tyson who were "shot" before the end of their 20's:
Domminick Guinn - 29 when he lost to Monte Barrett, never recovered
John Tate - 25 when he lost to Mike Weaver, never recovered
Donovan 'Razor' Ruddock - wasn't the same after the 2nd loss to Mike Tyson at age 28
Joe Mesi - he just misses the cut having only just turned 30 when he squeaked by Monte Barrett, he wasn't the same after that either.