William Edmondson's The Boxer realised $785,000 at Christie's on January 22, beating an estimate of $250,000 by 214%.
The lot led the Liberation through Expression sale of American outsider art in New York on January 22.
Edmondson (1874-1951) was a janitor who embarked on a career as a stonemason after receiving a message from God. He started out making tombstones before moving into sculpture.
His work caused a sensation in the art world, leading to a 1938 solo show at New York's Museum of Modern Art (MOMA).
Christie's comments: "Boxer is an incredibly sophisticated object. Likely modeled after Joe Louis, it is one of the most important sculptures created in interwar America�Ǫ
"One of only two pugilists carved by the artist, Boxer is a reflection of American popular culture of the era and shows Edmondson's pride in his cultural identity.
"Kept on a shelf protected by an overhang in Edmondson's Nashville, Tennessee yard, Boxer was by many accounts one of the artist's favorite works."
Martin Ramirez's Untitled (Seven Stags) was another highlight, achieving $75,000.
Ramirez was a paranoid schizophrenic who spent much of his life in various US institutions. One of his doctors noticed his remarkable artistic talent and provided him with materials.
His work was exhibited in galleries as that of an anonymous mental patient and was not shown under his name until many years after his death.
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