Floyd Mayweather Jr. vs. Cory Spinks on the horizon...

[Kev]

Leonard and Jones Jr also did it

Leonard didn't he won titles from welter to super middle thats 4 divisions. In fact only 3 because his supermiddleweight title was fought at 160, the middleweight limit, dont ask me why.

Jones Jr did and the was the only man in history to achieve that feat and he didn't come close to knocking Ruiz out.

Even the great Roberto Duran didn't he knocked out Barkley at middleweight, that's a climb of 4 divisions.

umm no Leonard won up to the Lightheavyweight title making him the first 5 weight class champion, Hearns the 2nd, and Oscar the 3rd
Leonard beat Lalonde at supermiddle it was a catchweight fight and Leonard weighed in at 167

Jones almost dropped Ruiz in the 6th i believe, wobbled him bad with a straight right

Ok but as you said that was at 167 so supermiddleweight, hence 4 weight classes not 5.