LONDON, United Kingdom — Christie's narrowly beat out rival Sotheby's in a billion-dollar week for both auction houses, thanks in part to eight-figure sales by bold-faced artists.

Christie’s sold $1.1 billion in the past week, while Sotheby’s moved $1 billion of art, jewellery and watches, according to press releases from both companies.

The Christie’s haul was padded by the $90.3 million sale of David Hockney’s “Portrait of an Artist (Pool with Two Figures)”, who eclipsed Jeff Koons as the most expensive living artist to sell at auction. A new record for American art was also set by the company with the $92 million sale of Edward Hopper’s “Chop Suey.”

Billionaire currency trader Joe Lewis was the seller of the Hockney. The Hopper came from the collection of deceased businessman Barney A Ebsworth. The buyers weren’t disclosed.

The highlight at Sotheby’s was the sale of a pearl and diamond necklace once owned by Marie Antoinette. The jewels sold for $36.2 million. The auction house said it’s had a 15 percent increase over last year in sales of impressionist, modern and contemporary works.

Phillips, a smaller auction house, announced $88.5 million of sales, with works from Joan Miro, Andy Warhol and Jean-Michel Basquiat bringing in the largest sums.

By Caleb Melby; editors: Matthew G Miller and James Ludden