Since Francis Bacon’s “Three Studies of Lucian Freud” (1969) sold at Christie’s for $142.4 million in New York last November a rash of paintings by that Irish-born artist have emerged for sale. The auction at Sotheby’s on Monday night, which kicked off the contemporary art sales here, will be remembered for buoyant bidding on a triptych by Bacon from 1964, which brought $45.4 million, well above its $33.6 million high estimate.

Four telephone bidders fought for the painting, “Three Studies for Portrait of George Dyer (on Light Ground),” which depicts the artist’s lover and was painted at the height of their affair.