A Modigliani nude painting was sold to an unnamed Chinese buyer at Christie’s on Monday for $170.4 million, the second-highest price ever for a work of art at auction, as deep-pocketed collectors continue to pay, and pay big, for some rare masterpieces up for sale in this year’s autumn auctions season.

The final price for the 1917-18 portrait “Nu couche” (Reclining Nude) — under the hammer for the first time ever — was second only to Picasso’s “Les femmes d’Alger” (Women of Algiers) which sold for $179 million at Christie’s in May.

While the buyer was not identified, Christie’s said the painting was bought by a private Chinese collector. Asian collectors have been especially active in the art market for the past several seasons.

Some half-dozen bidders competed for the canvas, which had remained in the same private collection for some 60 years and was offered as the highlight of a specially curated Artist’s Muse sale comprising 34 works in total.

In a packed salesroom marked by deliberate but determined competition, bidding started at $75 million — already more than Modigliani’s auction record of $70.7 million — and ticked upward in $5 million increments before an unidentified telephone bidder prevailed at $152 million.

The final price was $170,405,000, including Christie’s’ commission of just over 12 percent. The auction house had estimated the canvas would fetch more than $100 million.

While nearly 30 percent of the Artist’s Muse offerings went unsold — Lucian Freud’s “Naked Portrait on a Red Sofa” was estimated at as much as $30 million but failed to sell — the auction took in $494.4 million in total. That was right in the middle of the presale estimate of $442 million to $540 million.

Nodding to the sale’s unsold lots, Christie’s’ global president and auctioneer Jussi Pylkkanen said that was the risk of “pushing the envelope.” He noted some works were either not fresh to the market, or were perhaps aggressively priced.

But strong prices for top works that did sell bore witness to what Pylkkanen called “a masterpiece market” that was fomenting “extraordinary competition.”

A new record was set for an auction sale of work by Roy Lichtenstein, the pop artist best known for his vibrant, cartoon-style works. His 1964 painting “Nurse” fetched $95.4 million, within the $80 million to $100 million estimate.

Another artist record, for a Gauguin sculpture, was broken when “Therese” sold for just under $31 million, beating the $25 million estimate.