The 38 year-old began the fight well, but the hard-hitting Perez took over in the second half of the fight and was eventually handed a 117-111, 115-113 triumph on two of the judges cards, with the third scoring it a draw.
Spadafora missed out on equalling the great Rocky Marciano’s record of 49 wins without defeat as Perez picked up the interim WBA light-welterweight title and moved closer to a shot at 140lb king Danny Garcia.
A fight with Floyd Mayweather Jr. had long been talked about for Spadafora due to their similar records, although that fight now looks dead in the water after this maiden setback.
Elsewhere, former super-middleweight world title holder Jeff Lacy made a successful comeback after three years out of the ring by stopping Martin Verdin in three rounds the Belle of Baton Rouge Casino in Louisiana.
‘Left Hook’ Lacy, 36, last fought when losing to unheralded journeyman Dhafir Smith via a unanimous decision and pushes his record to 26-4 with the 18th knockout of his career to date.
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