Lucan (1977)

Lucan becomes a prizefighter to pay the bills for a private detective to find his parents. The private detective is just using Lucan stringing him along with false leads just to bilk him out of money. Fight promoters ask offer a cut of their expected illegal wager proceeds when they ask Lucan to throw a fight. If Lucan does not take a fall in the 10th round his doctor friend being held hostage will be killed by the folks in line to profit from the rigged fight. Lucan with help of a friend manages to turn the tables on the criminals get his doctor friend back and escape Police Detective Prentiss.