Its got to be ODLH he beat Jeff Mayweather with only 4 pro fights, he then beat Troy Dorsey with 6 pro fights, he then won Super Featherweight title with only 11 pro fights. And then after that he fought good opponent's after good opponents. Also Evander Holyfield fought decent opposition then he beat Dwight Muhammad Qawi only after 11 pro fights, he then demolished every single good Cruiserweight there was to beat, he then moved up and started fighting the best the Heavyweight division had to offer.