July 1925.
Jimmy McLarnin beats the reigning World Flyweight Champion commonly known as Pancho Villa (real name Francisco Guilledo) in a non-title bout.
In the days leading to the fight, Villa's face became swollen due to an ulcerated tooth, and on the morning of the fight he went to a dentist to have the tooth extracted. Despite the pain and swelling, Villa insisted on going ahead with fight with McLarnin. Villa ended up spending most of the fight using one hand to protect his afflicted face and lost via a points decison.
Two days later Villa had three more ulcerated teeth pulled out.
Within the week it was then discovered that the infection had spread to Villa's throat and he was rushed into surgery, but he lapsed into a coma while on the table and died the following day, July 14, 1925, 17 days before he became 24 years old.
Meanwhile, back in Manila--the day before he died-- Pancho's wife gave birth to their son. In 1989, she swore that his death was caused by an intentional overdose of anesthesia: a gambling syndicate's conspiracy to murder Villa for losing to McLarnin.