A decision by the Film and Publications Board's Appeal Tribunal to overturn the classification of "The Spear" artwork was welcomed by the Goodman Gallery on Thursday.
"This victory has cemented the gallery's mission to uphold its status as an activist space, dedicated to nurturing freedom of creative expression in South Africa," it said in a statement.
"It has also set a crucial precedent for the future of visual art in this country. We believe that it was extremely important to legally challenge the principle of censorship of the arts."
FPB spokesman Prince Ndamase said on Wednesday this meant the painting was no longer subject to a rating of 16N, which the board introduced in July.
The Goodman Gallery appealed against the classification on September 17, on the grounds that it was "impermissible and unsustainable".
The gallery said the tribunal, chaired by University of KwaZulu-Natal Professor Karthy Govender, agreed with the gallery's argument that the painting could not be described as "sexual conduct" under the Films and Publications Act.
"The argument of the Films and Publications Board that the display of nudity is presumptively harmful to children cannot be correct," the gallery said.
"The argument would imply that Pablo Picasso's 'Nude Youth' painting and Michelangelo's sculpture of David would be deemed presumptively harmful for children."
"The Spear", painted by Cape Town-based artist Brett Murray, depicted President Jacob Zuma with his genitals exposed.