The evening sales at Christie's and Sotheby's last week demonstrated that while the market is suffering from a diminishing supply of high-quality and 'unseen' pictures, buyers are willing to spend at ever more dramatic levels when rare and historically important material does appear.
Here they fought eagerly over the best pieces to take the series to a record-breaking £78m total.
Christie's (25/20/12% buyer's premium) 43-lot evening sale on December 8, which included 19th century paintings as well as Old Masters, raised a £60.5m hammer total - higher than any previous Old Master sale worldwide.
This was largely down to a Raphael drawing that made £26m and a Rembrandt portrait that sold at £18m, matching the previous record for the artist.
With 28 lots finding buyers, the total was near the top end of the £44.9m-62.6m pre-sale estimate.
The star lots captured the media's attention and the ensuing prices heightened the media glow surrounding the Old Master market.
The most spectacular price was the £26m paid against a £12m-16m estimate for Raphael's Head of a Muse, setting a record both for the artist and for any drawing sold at auction.
The first major Raphael drawing to be seen since Study for the Head and Hand of an Apostle made £4.8m at Christie's in London in December 1996, it was in excellent condition and broke the previous high for a work on paper, $33m (£21.5m) paid at Sotheby's New York in November 2008 for Degas' pastel Danseuse au Repos.
The 12 x 83/4in (30.5 x 22.2cm) Head of a Muse was a black chalk study for a figure in the Parnassus fresco in the Vatican - one of the series of four frescos that are considered the artist's greatest masterpieces.
Reportedly being sold by the heirs of the British collector Norman Colville, it was underbid by London-based dealer Jean-Luc Baroni, who lost out to a buyer bidding on the phone via a member of Christie's New York staff.
The competition for the drawing was in marked contrast to that seen on Rembrandt's 1658 half-length portrait at Christie's.
Consigned by the Johnson & Johnson heiress Barbara Piasecka Johnson, whose Jusepe de Ribera Prometheus was one of the star lots in Sotheby's London's July series, it was estimated at £18m-25m but attracted only a single telephone bid and sold on low estimate.
Not deemed one of the Dutch Master's greatest portraits, it nevertheless matched the record set for a Rembrandt by Portrait of a Lady, aged 62, from 1632, which sold to the late Maastricht-based dealer Robert Noortman at Christie's in London on December 13, 2000 (although the buyer's premium this time was greater).
While another record was seen when Saint John the Evangelist by Domenico Zampieri, Il Domenichino (1581-1641) made £8.2m against a £7m-10m estimate, only a handful of other works at Christie's generated strong bidding.
This was also the pattern at Sotheby's (25/20/12% buyer's premium) evening sale of Old Master and British paintings on December 9, which saw 21 of the 50 lots fail to sell.
Taking this failure rate by lot into consideration, the £13.1m hammer total against a pre-sale estimate of £12.34m-18.41m indicates the importance of the top-performing lots.
This was most clearly evident in the record price for Sir Anthony Van Dyck's Self Portrait, which sold for £7.4m - making up more than half the sale's total - to the art investor and collector Alfred Bader in partnership with Philip Mould.
International bidding came from at least nine participants as the price for the 2ft x 19in (60 x 47cm) oval oil was pushed above pre-sale hopes of £2m-3m.
Painted in London in 1640, this was the last self-portrait by the artist and had been in the family collection of the Earls of Jersey since the 18th century.
Following the sale, veteran Milwaukee-based Mr. Bader said: "It's a beautiful painting, and it's for sale," echoing the comments by dealers and auctioneers about the inherent difficulty of sourcing good quality, fresh-to-market Old Masters.
The previous record for a Van Dyck was £2.7m for A Rearing Stallion at Christie's London in July 2008.
Much pre-sale attention had been focused upon a previously unrecorded Portrait of a Young Woman by Peter Paul Rubens, but the 2ft 10in x 2ft 2in (86 x 66cm) oil, which had not won universal admiration among the trade, failed to sell at Sotheby's against a £4m-6m estimate.
The unfinished canvas is thought to be an early work, painted in either Italy or Spain, and had been in an anonymous UK private collection for the past 25 years. However, there were reservations about the attribution and condition, and Sotheby's picture specialist George Gordon felt that it was also not helped by the atypical subject matter.
Mediocre works were also left on the shelf, but an artist's record was set by Girl Holding a Basket of Plums by the little-known 17th-century Dutch artist Cesar Boetius van Everdingen.
Estimated at £50,000-70,000, this attractive, market-fresh painting tempted a number of bidders and sold on the phone for £1m.
By Alex Capon