He was actually Filipino but took the name of the Mexican revolutionary when he began fighting. He beat the great Jimmy Wilde (who was coming out of retirement) for the flyweight title. He defended for 2 years with what is said to have been a very exciting style. In 1925 he had a wisdom tooth taken out then fouth Jimmy McLarnin in a fight where he took a bad beating around the mouth. Pancho Villa, the fighter, required surgery and died under anasthesia on July 14 1925. Villa the revolutionary died almost 2 years earlier to the day (July 20 1923). In my opinion, he deserves his legendary status as an early pioneer of the smaller weights but his career does not match up to those of Mark Johnson, Erik Morales, or Marco Antonio Barrera a couple weight classes up.
Wikipedia appears to disagree with me and says that Pancho Villa died following surgery.