Sold for an astonishing $57.37 million in New York on Monday was a bronze sculpture welded by Romanian-born sculptor Constantin Brancusi. The sculpture of a sleeping woman’s head—”La muse endormie”— by the pioneer of modernism sold after nine minutes of bidding at Christie’s impressionist and modern art sale, kicking off a week of high-profile art auctions expected to rake in hundreds of millions of dollars.

The 1913 sculpture was cast by Constantin Brancusi who spent most of his working career in Paris. Despite being valued pre-sale at $25-35 million, it was snapped up by an anonymous bidder for twice its intended price.

The second top selling lot was a Picasso portrait of his mistress, Dora Maar, called “Femme assise, robe bleue,” painted on the Spanish master’s 58th birthday, which sold for $45 million, Christie’s said.

The oil painting was originally owned by the artist’s friend and gallerist Paul Rosenberg, before being confiscated by the Nazis and being discovered and rescued by Rosenberg’s son.

It was later acquired by US financier, industrialist and art collector George David Thompson. It was valued pre-sale at $35-50 million.

Christie’s and Sotheby’s—the esteemed houses founded in 18th century London—are chasing combined sales of at least $1.1 billion in offering for auction hundreds of contemporary, modern and impressionist works of art this week in New York.

The top estimate for the week is a 1982 “Untitled” by Jean-Michel Basquiat—a skull-like head on a giant canvas in oil-stick, acrylic and spray paint—for which Sotheby’s hopes to smash a new auction record for the US artist at more than $60 million.

Much of the art being offered this season is fresh to market—84 percent of the works offered by Christie’s on Monday had never been offered at auction or have been off the market for 20 years or more. Christie’s said the evening sale of impressionist and modern greats, including Monet, Chagall and Fernand Leger, fetched $289 million.

Buyers from 35 countries registered to bid, with 42 percent American and 23 percent Asian buying by lot, said Jessica Fertig, senior Christie’s specialist in impressionist and modern art.

Picasso holds the world record for the most expensive piece of art sold at auction with his “The Women of Algiers (Version 0)” fetching $179.4 million at Christie’s in New York in 2015.