The art-market bubble just got a little bigger. Last night Sotheby’s sold $93 million in contemporary art at a sale that showed buyers are willing to fork over unprecedented sums for marquee artworks, even if the artist is still alive and breathing. With little fanfare, auction records were smashed all over the place.

“It’s still a rising tide,” said dealer Marc Glimcher, making his way down the crowded salesroom aisles after the auction. “The sale speaks pretty well of the buyers.” Ten records were set for works by individual artists sold at auction, including new highs for Mark Rothko, Thomas Demand, Gilbert & George, Yoshitomo Nara, Richard Phillips, Matthew Barney, Joan Mitchell, Piero Manzoni, and Mark Tansey. “We are very very very happy with the results,” said auctioneer Tobias Meyer.

Contemporary art is the flavor of the week, with sales last night at Sotheby’s and tonight at Christie’s. Phillips de Pury & Co. started the week strong on Monday with a sale of contemporary photography and will end it on Thursday with its various-owner sale. As auctioneer and owner Simon de Pury said Monday, while selling Barbara Kruger’s 1983 “Untitled (I Shop Therefore I Am)” for a world record $601,600, “You bid, therefore you are.”

This week’s auctions follow a series of Impressionist and Modern art sales that showed the market to be strong, yet selective. “It was a sobering moment last week at Sotheby’s,” said dealer David Zwirner. “The estimates were too high for that kind of work. It was good to see a ceiling.” At the moment, the market for contemporary art seems deeper and stronger.

Last night, a blue, yellow, and white canvas by Mark Rothko, estimated at $9-12 million, was the star lot. “It’s the only thing worth bidding on,” said London-based collector Charles Hackmey before the sale. Wrapped in his olive overcoat and seated in the front row, Mr. Hackmey gave his paddle a workout. But he stopped around $10 million – the same price he paid last week to win a van Gogh at Christie’s. In the end, “No. 6 (Yellow, White, Blue Over Yellow on Gray)” went for more than that so-so van Gogh: Dealer Dominque Levy and a phone bidder went to the mat for the classic 1954 painting. Finally, the phone bidder won out, and the $17.4 million paid was a world record for a work by the artist.

Rothko painted “No. 6” in the same year he was offered his first major museum show, at the Art Institute of Chicago. Eight works were exhibited there, including “No.6,”which was insured for $2,000. Four pieces from that show are now in museums; two are owned by Rothko’s son and daughter; and two are in private collections.

The piece came from a collector who had acquired it from C&M Arts in the mid-1990s.It first appeared at Christie’s in May 1987, selling for $924,000. Some dealers said the painting had a strong estimate, tagging $6-8 million as a fair retail price. But they evidently underestimated the appeal of the painting. And this wasn’t the only high-profile Rothko transaction of late; dealers say around 10 Rothkos have been sold recently on the private market.

Bidders also went wild for three works by Jasper Johns, consigned by music mogul David Geffen. The star of the group was a large 1961 charcoal-and-pastel drawing, “0 Through 9.” The drawing’s subject is ostensibly neutral: numbers. But many have noted human elements in the paintings. A prominent passage in the lower left of the compositions appears to be a voluptuous human behind, of indeterminate gender. Scholars have suggested that much of Johns’s work contains homoerotic references, and this 1961 drawing was made soon after the artist’s bitter break-up with his lover of eight years, artist Robert Rauschenberg.

The Johns drawing was the second highest-priced lot of the night, selling for $10.9 million to a phone bidder, against an estimate of $7-9 million. This is not surprising, especially since MoMA recently acquired a Johns drawing, “Diver,” in 2003 – said to be worth $10 million – underlining the importance of the artist’s works on paper. Two Johns paintings, also from Geffen, sold strong. The 1956 9-inch-by-9 inch wax and newspaper collage “Green Target” brought $3.7 million from a man who bid wearing sunglasses. A later wax collage, the 1971 “Flag,” brought $4.5 million.

Guaranteed property had no trouble selling. During the Impressionist and Modern sales last week, a collection of Modernist paintings consigned by former dealer Hester Diamond had been deemed too pricey, and two major works from the Diamond collection failed to sell (estimated $28-42 million). But last night that wasn’t a problem.

Three important paintings came from dealer Alberto Mugrabi, who had demanded a large guarantee. Andy Warhol’s 1963 “5 Deaths Twice 1 (Red Car Crash)” was expected to sell for $5.5-6.5 million. It had last appeared at auction at Sotheby’s New York in May 1989, when it sold for $522,500. Last night an American private collector bought it for $6.5 million. Mr. Mugrabi also had consigned Jeff Koons’s “Bracelet,” which went for $2.3 million, and Jean-Michel Basquiat’s 1982 “Offensive Orange,” estimated at $2.5-3.5 million, which sold for $3 million to a European private collector.

Records were also set for a number of artists who had been undervalued on the auction market. Joan Mitchell’s “King of Spades,” a classic AbEx work from 1956, more than doubled Mitchell’s previous auction record, bringing $2.7 million from an American dealer. And with Minimalism heating up, it was only a matter of time before European Minimalists started getting some attention. Piero Manzoni’s white and rumpled 1959 “Achrome” set another record, selling for $1.8 million – well over the $1-1.5 million estimate.

Even the evening’s least popular picture set a record. Lot 59, when projected on the oversized screens above the auction room, drew fevered hissing from the audience. It was a whimsical 2001 portrait of President Bush by Richard Phillips, titled “The President of the United States.” Two blushing bidders raised their paddles, competing with a phone bidder. The victor was art advisor Daniella Luxembourg, who said she bought the piece for a client. At $142,400, it was a record for the artist, and a sign of the times. Money is no matter, and the smirk is back in style.