Prior to London’s art auctions last week, there was every reason to think that the sales would confirm the emergence of a truly global art market, in which the same faces appear in different places and Chinese contemporary art is purchased everywhere — except in China. But the conventional wisdom was upended; the sale of two nearly identical pieces by the artist Damien Hirst showed that markets contain mysteries and surprises, no matter how predictable they may appear.

Mr. Hirst became one of the world’s most expensive living artists last week when an anonymous buyer spent more than $19 million for “Lullaby Spring” (2002). The work features a large medicine cabinet-like vitrine holding rows of shelves with tiny bronze-casts painted to look like pills. Given the hype around Mr. Hirst’s diamond-studded skull sculpture on offer at his gallery for $100 million, the price for “Lullaby Spring” might seem cheap — except that in May Christie’s sold “Lullaby Winter” (2002) for $7.4 million, which at the time set a new record for Mr. Hirst. (In defense of the buyer, “Lullaby Spring” does contain more pills in a brighter variety of colors.)

The jump in price to $19 million from $7.4 million is extraordinary, even for this art market. Perhaps it was timing that accounted for one buyer’s willingness to spend nearly $12 million more than another. Perhaps the sale awakened collectors who just had to have the next “Lullaby” work that came to market. A similar situation occurred in London in February when a bidding war drove a Peter Doig painting to $11 million. His works normally range between $1 million and $3 million; in the recent auctions, his prices have returned to that range.

If money is any indication, the London sales have momentum. Christie’s reported a nearly 20% rise between the February sales and June sales. The total for the Impressionist, Modern, and Postwar Contemporary sales rose to $470 million from $392 million. Sotheby’s sold $408 million worth of art, their highest London total ever.

Overall, the London auctions showed that the steady trends of the last two years are still in train. The big names are mostly getting bigger — though the market will not absorb just anything by an iconic artist — and there are a number of reputations that are still shifting and solidifying. The auction houses have set strong estimates, often reflecting the equally strong guarantees they are forced to give to secure business, but most works are selling in the range with a few sales that double or, even triple, the estimates.

The headline artists — Monet, Matisse, Hirst, Basquiat, Freud, and Bacon — somewhat overshadowed the real story of these sales: very strong prices for European artists such as Piero Manzoni, Lucio Fontana, and Yves Klein. These are artists are sold in New York with prices above the highestimates. (Indeed, that is part of the evidence for the global art market.) But in London there were many more paintings and the prices were much higher. Christie’s set a record for Manzoni with a 1958–59 “Achrome” painting selling for $4.27 million. Sotheby’s set a record for Fontana at $4.9 million for a 1965 “Concetto Spaziale.” And Klein had two canvases in Christie’s top 10 sales from the Postwar sale.

Chinese painters, too, made their mark in London. Sotheby’s set a record $4.28 million for “The Pope” (1997), a painting of the artist Yue Minjun dressed as a Pope Innocent X. Echoing Bacon, and a dozen other painters and ideas, Yue’s work is everywhere at auction these days. And Yue is hardly the only Chinese painter selling well.

Phillips de Pury wrapped up the auction week Friday. The house scored well last week with a Warhol “Self-Portrait” (1966) for $3.6 million and Baquiat’s “Grillo” (1984), which sold for $10 million. But the signal success was the record prices they achieved for six different Chinese painters, including Zhang Xiaogang.

Pushing the boundaries of international art further, Phillips also set records for a half a dozen Russian artists. All of which suggests the international art market is indeed finally becoming truly global in both supply and demand.