Damien Hirst's iconic sheep in formaldehyde sculpture broke the auction record for the British artist at a sale in New York.
Hirst used formadehyde in many of his pieces
The piece, called Away From the Flock Divided, was bought for $3.4m (£1.8m) by an American art dealer.
The top lot at the post-war and contemporary art sale was Andy Warhol's Small Torn Campbell Soup Can from 1962, which sold for $11.8m (6.3m).
The first day of the sale at Christie's raised more than $143m (£76m).
Among other lots exceeding expectations was Warhol's S&H Green Stamps, which fetched $5.2m (£2.7m) - four times its pre-sale estimate.
Other artists featured in the sale included David Hockney, Brice Marden and Donald Judd.
It was a good night for works by Willem do Kooning, with an untitled 1961 piece reaching $10.1 (£5.4m), while Two Women (Study for Clamdigger) reached $5.7m (£3m)
Pieces by Francis Bacon and David Smith failed to sell.
The second day of the sale on Wednesday includes a collection of important photographic prints from the archive of the bankrupt US brokerage firm Refco.