A painting from Cy Twombly's Blackboard series realised a record $70.5m at Sotheby's New York on November 11.
The piece beat the previous record for a Twombly, $69.6m set at Christie's in 2014.
Anthony Grant, Sotheby's vice president in the Americas, said: "The date, scale, and distinguished provenance of Untitled, 1968 [New York City] place it as one of the most important examples of Cy Twombly's celebrated 'Blackboard' series remaining in private hands.
"It is always a pleasure to welcome spectacular works of art back to Sotheby's - we last offered the painting in 1990 as part of the Saatchi Collection.
"The brilliance of the artist's gestural genius is on full display as the written form dissolves into a nuanced grey background."
Other lots included Andy Warhol's silkscreen portrait of Chairman Mao, which sold for $47.5m.
It's one of the few series in Warhol's oeuvre that he worked on entirely by himself, without the use of assistants.
He was inspired to create the portrait following Nixon's visit to China in 1971, which kicked off a gradual thawing between the two nations.
It uses Mao's iconic state portrait and is painted in Warhol's unique style. A smaller version sold for £7.6m ($12.2m) at Sotheby's last year.
Please sign up to our free newsletter to receive exciting news about art and photography auctions.