Who was the last fighter to have more than a 100 pro bouts, before challenging and winning a generally considered major World title?
Are you asking for first time champions exclusively, or can former champions winning a subsequent title also be included?
The question says over a 100 bouts, so I don't suppose Jorge Fernando Castro counts... since he won the WBA middleweight crown in 1994 in his 100th fight?
The first time they received a shot. Like say Archie Moore who fought and beat Maxim at his first attempt at a world title in his 160th bout...
Good guess, Moore certainly fits the criteria, but it was later than the Ol' Mongoose's win over Maxim.
Nicolino Locche looks pretty good Ramon La Cruz fought for the title in his 1st World Title bout in October 1968 in his 106th bout. Luis Federico Thompson & Duilio Loi both had over 100 bouts when they 1st fought for a World Title in 1960.
Jeff Malcolm in 1991 I didn't read the question right, sorry! Jeff Malcolm challenged for the WBO Title but didn't win it. He did win the WBF in 1994