It took seven superrich bidders to propel a 1969 Francis Bacon triptych to $142.4 million at Christie’s on Tuesday night, making it the most expensive work of art ever sold at auction. William Acquavella, the New York dealer, is thought to have bought the painting on behalf of an unidentified client, from one of Christie’s skyboxes overlooking the auction.

The price for the painting, which depicts Lucian Freud, Bacon’s friend and rival, perched on a wooden chair, was more than the $85 million Christie’s had estimated. It also toppled the previous record set in May 2012 when Edvard Munch’s fabled pastel of “The Scream” sold at Sotheby’s for $119.9 million and broke the previous record for the artist at auction set at the peak of the market in May 2008, when Sotheby’s sold a triptych from 1976 to the Russian oligarch Roman Abramovich for $86.2 million.

When the bidding for “Three Studies of Lucian Freud” finally stopped, after more than 10 fraught minutes, the overflowing crowd in the salesroom burst into applause. Two disappointed bidders could be seen leaving the room. “I went to $101 million but it hardly mattered,” said Larry Gagosian, the super-dealer who was trying to buy the painting on behalf of a client. Another contender was Hong Gyu Shin, the director of the Shin Gallery on Grand Street in Manhattan, who said he was bidding for himself.

“I was expecting it to go for around $87 million,” Mr. Shin said. Although he explained that he collects mostly Japanese woodblock prints and old master paintings, he found the triptych by the Irish-born painter, who died in 1992, irresistible. “I loved that painting and I couldn’t control myself,” he said. “Maybe someday I’ll have another chance.”