An untitled "blackboard" work by Cy Twombly sold for a record-setting $70.5 million at Sotheby's on Wednesday, leading the way to a $295 million total at the auction house's sale of contemporary and post-war art.

The untitled oil and crayon-on-canvas from 1968, one of the artist's seminal blackboard works meant to resemble chalk on blackboard, was sold to an anonymous client and exceeded Sotheby's' estimate of a sale price in excess of $60 million.