The late Michael Chapdelaine claimed he was the only person to win the world's top competitions in both "fingerstyle" and "classical" guitar: Winfield's National Fingerpicking Champion and the Guitar Foundation of America's International Classical Guitar Competition. While I haven't had time to research this claim, after hearing Chapdelaine's CDs I have every reason to believe it's true.
After two decades of great success as a Classical guitarist, Chapdelaine, who studied with Andrés Segovia, shifted gears and re-invented himself. "A guy who used to have a tuxedo" (his line) now performed barefoot, knocking out incredible one-man band arrangements of pop hits from the 60s, 70s, and 80s.