She told the BBC: "There's a market which is sort of exceptional for exceptional things.
"If something is a one in a lifetime opportunity, people will really step up to the plate and they will spend enormous amounts of money because it was a now or never opportunity."
The previous record for an art work sold at auction -$104,168,000 (£58,520,830) - was held by Pablo Picasso's Garcon a la Pipe which sold in New York in 2004.
Other works have reached more in private sales. Jackson Pollock's No5, 1948, reached $140m (£73m at the time) in 2006.
The sculpture had been expected to sell for between £12m and £18m
Another art work also exceeded expectations at Sotheby's Impressionist and Modern Art sale.
Gustav Klimt's Kirche in Cassone went for £26,921,250, above the £12m to £18m estimate.
Paul Cezanne's Pichet et fruits sur une table was sold for just under £12m.
Melanie Clore, of Sotheby's Impressionist and Modern Art department, said: "We are thrilled to have sold these great works this evening and that they have been recognised for the masterpieces that they are.
"The competition which generated these exceptional results demonstrates the continued quest for quality that compels today's collectors."
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