I'm pretty sure a few of George Foreman's opponents were dropped by jabs too.
Big George KO'ed Bob Hazelton with a jab in 1969!
http://www.youtube.com/watch?v=NOVM9DiY4KA
Muhammad Ali vs Cleveland Williams
Joe Frazier vs Bob Foster
George Foreman vs Ken Norton (and maybe Frazier II)
Sonny Liston vs Wayne Bethea
Joe Louis vs Max Baer and Buddy Baer II