Contemporary art ($1.6bn/up 20.3%) and Impressionist & Modern art ($1.4bn/up 26.7%) dominate sales, accounting for half the entire auction total.
Sotheby's also highlighted the importance of new buyers, who represented a third of all buyers and accounted for close to a fifth of sales.
The auctioneers report that what they refer to as Greater Chinese clients spent more than $1bn globally at auction.
And they enjoyed their best ever single-owner offering when The Collection of Mrs Paul Mellon took $218m including premium across there sales.
Sotheby's full set of results are expected in a few weeks' time.