Brit artist Damien Hirst smashed his previous auction record with the $18.5 million sale of a gold tipped bull in formaldehyde on the first day of his major solo sale at Sotheby's in London Monday. Entitled The Golden Calf, the controversial artist's work exceeded the top end of its estimate by over $4 million, and toppled the previous record of $17.4 million paid for a Hirst work last summer, Bloomberg reports. The buyer's identity is unknown at this time.

Fifty-four lots went under the hammer, raising more than the conservative pre-sale estimate of $130 million for the entire two-day event.

Hirst is selling 223 new works directly through Sotheby's in the "Beautiful Inside My Head Forever" sale, saving millions by cutting out dealers' commission. The upper estimate for the whole event is $196 million.